The publishing and editorial teams would like to thank the following, for their invaluable service as 2021 reviewers for this journal. We are very grateful for the contributions made. With their help, the journal has been able to publish such high-quality articles:

• A, Prakash
• Abbasi, Maysam
• Abdulrahman, Kamil
• Adriano, Ricardo
• Aghaee, Toktam
• Agrawal, Yash
• Ahmadpour, Ali
• Ahmed, Suhaib
• Aissaoui, Abdel Ghani
• Akuru, Udochukwu
• Al-Saidy, Haider Fakher Radhi
• Alagu, Matheswaran
• Albadarneh, Ramzi
• Alfonzetti, Salvatore
• Alfonzetti, Salvatore
• Alotto, Piergiorgio
• Amara, Yacine
• Andjelic, Zoran
• Antonopoulos, Christos
• Astik, Mitesh
• Aubert, Herve
• Awah, Chukwuemeka
• Aydogmus, Omur
• Badics, Zsolt
• Baghayipour, Mohammadreza
• Balabozov, Iosko
• Baldan, Marco
• Ban, Tian
• Banu J, Barsana
• Baoming, Ge
• Baranski, Mariusz
• Barbulescu, Constantin
• Bardi, Istvan
• Barmpatza, Alexandra
• Barukcic, Marinko
• Başaran, Kıvanç
• Bauernfeind, Thomas
• Bay, Francois
• Belli, Zoubida
• Ben Regaya, Chiheb
• Benšić, Tin
• Berenger, Jean-Pierre
• Biabani, Sadegh
• Bigdeli, Mehdi
• Bilicz, Sandor
• Bindu, G R
• Bird, Jonathan 
• Biro, Oszkar
• Boonruk, Chipipop
• Bou-Rabee, Mohammed
• Boudouda, Aimad
• Boukhnifer, Moussa
• Boynov, Konstantin
• Brudny, Jean
• Buchau, André
• Bulić, Neven
• Burlikowski, Wojciech
• Butrylo, Boguslaw
• Cabral, Sérgio
• Cai, Shun
• Caner, Murat
• Cardoso, Jose
• Castaldi, Giuseppe
• Ceclan, Andrei
• Çelikel, Reşat
• Chaber, Bartosz
• Chabu, Ivan 
• Chadebec, Olivier
• Chamundeeswari, V
• Chen, Haijin
• Chen, Xi
• Cheng, Zhiguang
• Chervenkov, Atanas
• Chisepo, Hilary
• Chitarin, Giuseppe
• Chwastek, Krzysztof
• Clemens, Markus
• Clenet, Stephane
• Codecasa, Lorenzo
• Condon, Marissa
• Costamagna, Eugenio
• Cui, Xiang
• Da Costa Neves, Carlos Guilherme
• Da Silva, Aderiano
• De Souza Jr, Antonio
• De Tommasi, Luciano
• Degersem, Herbert
• Dehbovid, Hadi
• Demirtas, Mehmet
• Demirtas, Metin
• Dems, Maria
• Devaraj, D
• Devarapalli, Ramesh 
• Di Barba, Paolo
• Ding, Qiang
• Djeghloud, Hind
• Doležel, Ivo
• Doležel, Ivo
• Drosopoulos, Anastasios
• Duchesne, Stéphane
• Dufour, Stephane
• Dupre, Luc
• Eckert, Paulo
• Elkholy, Mahmoud M.
• Erdin, Ihsan
• Exnowski, Sven
• Fan, Chaodong
• Fei, Juntao
• Filipova-Petrakieva, Simona
• Filippini, Mattia
• Fireteanu, Virgiliu
• Fišer, Rastko
• Foglia, Giovanni
• Forghani, Behzad
• Formisano, Alessandro
• Forzan, Michele
• Galadi, Abdelghafour
• Ganji, Ehsan
• Garbuio, Lauric
• García-Moreno, Salatiel
• Gerbaud, Laurent
• Germishuizen, Johannes
• Geuzaine, Christophe
• Ghaebi Panah, Payam
• Ghaffari, Valiollah
• Ghnatios, Chady
• Gholami, Khalil
• Ghorbanian, Vahid
• Giannacopoulos, Dennis
• Gołębiowski, Marek
• Goleman, Ryszard
• Golosnoy, Igor
• Gong, Xun
• Görgülü, Sertaç
• Gratkowski, Stanislaw
• Gupta, Preeti
• Gürses, Barış
• Gwozdziewicz, Maciej
• Habibzadeh, Ameneh
• Hadjiaghaie Vafaie, Reza
• Hadjout, Larbi
• Hajji, Sofien
• Hameyer, Kay
• Han, Shouyi
• Handgruber, Paul
• Hashemi, Seyed Amir
• Heidarian, Mahdi
• Henrotte, Francois
• Hinov, Nikolay
• Hollaus, Karl
• Horla, Dariusz
• Hua, Hao
• Iamamura, Juliana
• Ibrahim, Issah
• Illahi, Fazal
• Illias, Hazlee Azil
• Ilten, Erdem
• Iqbal, Muhammad Sajid
• Ispirli, Mehmet
• Izadbakhsh, Alireza
• J., Catherine
• Janousek, Ladislav
• Janssen, Rick
• Javadifar, Nader
• Jażdżyński, Wiesław
• Jebaraj, Luke
• Jerkan, Dejan
• Joksimovic, Gojko
• Justin Nayagam, Brintha Jane Justin
• K, Eswaramoorthy
• Kaczmarek, Michał
• Kalenderli, Özcan
• Kallio, Samuli
• Kaltenbacher, Manfred
• Kaminski, Marcin
• Kanai, Yasushi
• Kantartzis, Nikolaos
• Kapłon, Andrzej
• Karakas, Ercument
• Karwowski, Andrzej
• Katic, Vladimir
• Kawase, Yoshihiro
• Kefalas, Themistoklis
• Khamil, Khairun Nisa
• Khan, Shafiullah
• Kim, Hi Seok
• Kirei, Botond Sandor
• Kiyoumarsi, Arash
• Koester, Niels 
• Kolondzovski, Zlatko
• Komarzyniec, Grzegorz
• Komeza, Krzysztof
• Korzeniewska, Ewa
• Koteras, Dariusz
• Krishna S, Mohan
• Kruchinina, Irina
• Kumar, Narinder
• Kumar, Venkatesh
• Lahiry, Archiman
• Lakhdari, Ala Eddine
• Lanfranchi, Vincent
• Latifizadeh, H. 
• Lattarulo, Francesco
• Lazovic, Luka
• Leal, Danielle
• Lebensztajn, Luiz
• Lefevre, Yvan
• Lefik, Marcin
• Leonowicz, Zbigniew
• Lewandowski, Michał
• Li, Gang
• Li, Liang
• Li, Lin
• Li, Ya
• Liu, Lilan
• Lopato, Przemyslaw
• Lotfy Al Azzab, Khaled
• Lowther, David
• Lu, Qinfen
• Lukaniszyn, Marian
• Lv, Pin
• M, Karuppasamypandian
• Ma, Qingqing
• Magdowski, Mathias
• Magele, Christian
• Mahdavi, Mojdeh
• Majumdar, Payal
• Mariani, Viviana
• Márquez-Martínez, Luis Alejandro
• Martone, Raffaele
• Masroor, Suhaib
• Mazlumi, Farhad
• Md. Saat, Mohd. Shakir
• Merzouk, Imad
• Mininger, Xavier 
• Miorelli, Roberto
• Mladenov, Valeri
• Młot, Adrian 
• Mognaschi, Maria Evelina
• Mohsen, DENDEN
• Moreno, Pablo
• Morev, Andrey
• Moro, Federico
• Munteanu, Calin
• Murugan, A.S.S.
• Murugesan, Srinivasan
• N.B, Prakash
• Nabavi  , Abdolreza 
• Nafea, Marwan
• Naghizadeh, Ramezan Ali
• Napieralska-Juszczak, Ewa
• Nasir, Mohammad
• Nasiri, Mojtaba
• Nastasi, Giovanni
• Netter, Denis
• Nowak, Lech
• Nunes, Anderson 
• Pachauri, Nikhil
• Paknys, Robert
• Palka, Ryszard
• Paplicki, Piotr
• Pasko, Marian
• Pasupulati, Baburao
• Pati, Avadh
• Pavo, Jozsef
• Perkkiö, Lauri
• Petkovska, Lidija
• Petrasova, Iveta
• Petrun, Martin
• Pichon, Lionel
• Pietrzak, Lukasz
• Piriou, Francis
• Pisano, Fabio
• Pleshivtseva, Yuliya
• Pokanati, Rama Rao
• Polajžer, Boštjan
• Popa, Gabriel Nicolae
• Przybylski, Marek
• Quesada-Pereira, Fernando
• R, Dr.R.Shivakumar
• R, Durga Devi
• R, Ramaprabha
• R, Zahira
• Radulovic, Vladan
• Rahideh, Akbar
• Rahimi, Tohid
• Rahman, Tanvir
• Rajni, Rajni
• Raniszewski, Grzegorz
• Rasool, Akhtar
• Rawat, Gopal
• Reinbacher-Köstinger, Alice
• Ren, Zhuoxiang
• Renhart, Werner
• Repetto, Maurizio
• Rezaee-Alam, Farhad
• Rezaeealam, Behrooz
• Riley, Chris
• Riyadi, Munawar
• Roger, Daniel
• Romano, Vittorio
• Romero, Murilo
• Ronkowski, Mieczyslaw
• Rosendahl, Jens
• Rozga, Pawel
• Rubinacci, Guglielmo
• S, Ganesan
• Sabariego, Ruth
• Sabri, Mahdi
• Sacco, Riccardo
• Saeed, Mahmoud
• Salerno, Nunzio
• Salvini, Alessandro
• Schneider, Carl
• Schneider, Michael
• Schöbinger, Markus
• Serhoud, Hicham
• Seyedtabaii, Saeed
• Shah, Sahas
• Shakouhi, Seyed Mohammad
• Shamshirband, Shahaboddin
• Shao, Jinghui
• Sharma, Abhinav
• Sharma, Anurekha
• Shen, Zhiyuan
• Silva, Elson
• Silva, Rodrigo
• Siodla, Krzysztof
• Smajic, Jasmin
• Smolka, Krzysztof
• Souissi, Amal
• Specogna, Ruben
• Stachowiak, Dorota
• Stawicki, Krzysztof
• Stošić, Biljana
• Stuikys, Alex
• Štumberger, Gorazd
• Sui, Yi
• Sun, Xiaodong
• Superczynska, Paulina
• Szymanski, Lukasz
• Taghikhani, Mohammad Ali
• Taghipour Boroujeni, Samad
• Takahashi, Yasuhito
• Tang, Yue
• Tang, Zuqi
• Tani, Angelo
• Teixeira, Julio Carlos
• Ter Maten, Jan
• Tir, Zoheir
• Torchio, Riccardo
• TÖREN, Murat
• Torkaman, Hossein
• Tortella, Andrea
• Touré, Baidy
• Trawiński, Tomasz
• Tsukerman, Igor
• Tytko, Grzegorz
• Uddin, Moiz
• Urbanski, Konrad
• V, Veerapandiyan
• Vandevelde, Lieven
• Vaseghi, Babak
• Vasudevan, Saravanan
• Velu, Gabriel
• Venkateswara Rao, B
• Verma, Amit
• Vieira, João
• Vittek, Jan
• Vlachogiannis, John
• Vollaire, Christian
• Waindok, Andrzej
• Wajnert, Dawid
• Wang, Jiawei
• Wang, Quan-Quan
• Wang, Shuang
• Wang, Xingyuan
• Wardach, Marcin
• Wu, Di
• Wu, Zhongze
• Xia, Bin
• Xiao, Qing
• Xiaohua, Bao
• Yang, Zebin
• Yatchev, Ivan
• Youcef, Ouazir
• Yu, Siyang
• Zenczak, Michal
• Zhang, Changgeng
• Zhang, Fang
• Zhang, Feng
• Zhang, S
• Zhang, Wei
• Zhao, Xiaojun
• Ziaja, Jan
• Ziedan, Nesreen
• Žilková, Jaroslava
• Ziolkowski, Marek
• Zirka, Sergey
• Zitouna, Bessem
• Zurek-Mortka, Marta