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:

• Abbas, Jannat
• Abdlaziz, Rizgar
• Abdulqadir, Idris
• Abrar Ul Haq, Muhammad
• Acevedo, Rafael
• Acharya, Rajesh
• Ackah, Ishmael
• Acquah, Abraham
• Adabor, Opoku
• Adam, Abdul-Kahar
• Adebayo, Tomiwa
• Adekoya, Oluwasegun
• Adeosun, Opeoluwa
• Adetayo, Olorunjuwon
• Adi, Tri Wahyu
• Adjei, Eunice
• Ado, Abdullahi
• Aggarwal, Ashwini
• Aggarwal, S. K.
• Agyemang, Seth
• Ahad, Muhammad
• Ahmad, Nyarwi
• Aina, Oluwatimilehin
• Ajewole, Titus
• Akbar, Faraz
• Akram, Vaseem
• Alayi, Reza
• Alhassan, Abdulkareem
• Alhassan, Hamdiyah
• Ali, Ahmad
• Ali, Rashid
• Alkaldy, Esam
• Alqaralleh, Huthaifa
• Alsaleh, Mohd
• Alsultanny, Yas
• Alves, Carlos
• Ameyaw, Collins
• Anafo, Andrew
• Anangapal, Hari Bhaskaran
• Aneja, Ranjan
• Anthony Jnr, Bokolo
• Arabatzis, Garyfallos
• Aruga , Kentaka 
• Aruna, Bhagavatula
• Ashnavar, Mohammad
• Askari, Mohammad Bagher
• Asumadu, George
• Auer, Benjamin
• Avordeh, Timothy
• Awan, Ashar
• Azman Aziz, Mukhriz Izraf
• Babatunde, Olubayo
• Baghaei Daemi, Hamideh
• Bai, Caiquan
• Bananuka, Juma
• Batmunkh, Munkh-Ulzii
• Bezerra, Francisco
• Bhat, Mohammad
• Bhatnagar, Navdeep
• Bianco, Vincenzo
• Boateng, Emmanuel
• Borozan, Djula
• Bose, Saravanan
• Bugshan, Abdullah
• Burade, Prakash
• Burda, Yegor
• Burki, Umar
• Can, Hamit
• Castañeda-Ayarza, J. A.
• Chakrabarti, Anindita
• Chakraborty, Ayon
• Chaturvedi, Bhartendu
• Chatzitheodoridis, Fotios
• Chatzitheodoridis, Fotios
• Chehade, Saleh
• Chekouri, Sidi Mohammed
• Chew, Kuewwai
• Chitedze, Isaac
• Chong, Chin Wei
• Ciarreta, Aitor
• Dai, Qiyao
• Daiyabu, Yusuf
• Dar, Javaid
• Das, Anupam
• Datta, Banantika
• Delfin, Odette
• Di Foggia, Giacomo
• Di Fraia, Simona
• Digalwar, Abhijeet
• Dimnwobi, Stephen
• Donastorg Sosa, Angelines
• Duc Huynh, Toan Luu
• Ehtesham, Md
• El Islam Bachari, Nour 
• Elhegazy, Hosam
• Elshobary, Mostafa
• Erdoğan, Seyfettin
• Esa, Elinda
• Estrada, Mario Arturo
• Farhadi, Payam
• Ferraresi De Araujo, Geraldo Jose
• Furlonge, Haydn
• Gagnon, Stephane
• Gatto, Andrea
• Gavrikova, Elizaveta
• Goli, Alireza
• Gomaa, Mohamed
• Guang, Fengtao
• Halicioglu, Ferda
• Hashmi, Shujahat
• Hoang, Ha
• Hoseinzadeh, Siamak
• Hsieh, Jin-Chi
• Huang, Yun-Hsun
• Hutagalung, Aldi
• Islam, Md. Monirul
• Jaber, Jamal
• Jain, Naveen
• Jallal, Mohammed Ali
• Jarboui, Anis
• Jaya, Anthony
• Jean Gaston, Tamba
• Jednak, Sandra 
• Jethani, Jeevan Kumar
• Joon, Tùng
• Kaawaase, Twaha
• Kahla, Franziska
• Kanagaraj, Aruna
• Kassem, Mukhtar A.
• Kathuria, Vinishk
• Kayesh, Md. Safiullah
• Kelly, Solange
• Khatib, Tamer
• Khirbat, Manohar
• Khosrojerdi, Farhad
• Khurshid, Muzammil
• Kilinc-Ata, Nurcan
• Kirkulak-Uludag, Berna
• Klotzle, Marcelo
• Kocoglu, Mustafa
• Kogid, Mori
• Korkmaz, Özge
• Kumar, Deepak
• Kumar, Vikas
• Kushwah, Silky
• Lachman, Daniel
• Leal, Patrícia
• Lichinga, Kevin
• Lilies, Setiartiti
• Liu, Kai-Di
• Loizou, Efstratios
• M. Moustapha, Maman Ali
• M. Ibrahiem, Dalia
• Magazzino, Cosimo
• Mahanty, Biswajit
• Malesios, Chrisovaladis
• Mangano, Giulio
• Marcianò, Claudio
• Marques, Luís Miguel
• Martinez-Neri, Ivan
• Martins, Vitor
• Masood, Tariq
• Mawejje, Joseph
• Menzel, Tobias
• Mhd Sarif, Suhaimi
• Mirmozaffari, Mirpouya
• Mishra, Geeti
• Mohammadi Aylar, Salamoulah
• Morea, Donato
• Mosiño, Alejandro
• Mosner-Ansong, Kwabena
• Mugableh, Mohamed
• Nag, Barnali
• Naik, Shankara
• Naomi, Prima
• Naseem, N. A. M
• Nayar, Jayaram
• Nazari, Mohammad Esmaeil
• Nguyen, Nguyen Phuc
• Nisar, Saad
• Novikau, Aliaksandr
• Nwafor, Florence
• Ochieng, Edward
• Odoi-Yorke, Flavio
• Ohene-Asare, Kwaku
• Ojolo, Sunday
• Okwanya, Innocent
• Oloko, Tirimisiyu
• Olorunfemi, Felix
• Omri, Anis
• Onodje, Patrick
• Opoku, Richard
• Oskenbayev, Yessengali
• Owusu, Richard Afriyie
• Özgül, Ali Ulvi
• Palazzi, Rafael
• Pazhoohesh, Mehdi
• Pekanov Starčević, Dubravka
• Pellegrino, Roberta 
• Rafique, Raza
• Rahimi Ariae, Afrooz
• Rahman, Md. Hasanur
• Raifu, Isiaka
• Rauf, Abdul
• Rawat, Atul
• Ray, Amitava
• Rehman, Abdul
• Rej, Soumen
• Reyes-Mercado, Pável
• Ringel, Marc
• Sahu, Bikash
• Samuel, Olusegun
• Sandhu, Navjot
• Santillán Vera, Mónica
• Saraswat, Santosh
• Satapathy, Amitabh
• Satpute, Anand
• Sethi, Narayan
• Sevinç, Haktan
• Shahateet, Mohammed
• Sharmin, Mowshumi
• Siddiqui, Faiza
• Siepermann, Markus
• Simeon Adaka, Sunday
• Singh, Sri Niwas
• Singh, Brijesh
• Singh, Manjeet
• Skordoulis, Michalis
• Soni, Vivek
• Sreekanth, K. J.
• Sudarno, Sujono
• Sunder, Raju
• Tahir, Muhammad
• Tampubolon, Biatna Dulbert
• Thai Hung, Ngo
• Topcu, Mert
• Torkayesh, Ali
• Trimech, Anyssa
• Trinh, Nga
• Tripathi, Alok Kumar
• Tsolas, Ioannis
• U-Din, Salah
• Veiga, Claudimar
• Viego, Valentina
• Vishwakarma, Suresh
• Walls, W. D.
• Wang, Zihan
• Waris, Idrees
• Zahraee, Seyed Mojib
• Zhou, Decai
• Zullo, Emmanuel
• 杨, 国梁
• 章, 文杰