Wieslaw A. Dudek (Wroclaw, Poland)                  e-mail: wieslaw.dudek@pwr.edu.pl

V. A. Shcherbacov (Chisinau, Moldova)                  e-mail: scerb@math.md
P. Vojtĕchovský (Denver, USA)                                e-mail: petr@math.du.edu

M. Akram (Punjab, Pakistan)
V. A. Artamonov (Moscow, Russia)
A. Badawi (Sharjah, United Arab Emirates)
A. Drapal (Praha, Czech Republic)
T. Foguel (Auburn, USA)
A. D. Keedwell (Surrey, England)
T. Kepka (Praha, Czech Republic)
H. Kiechle (Hamburg, Germany)
H. S. Kim (Seoul, Korea)
M. K. Kinyon (South Bend, USA)
A. Krapez (Belgrade, Serbia)
G. L. Mullen (Pennsylvania, USA)
Q. Mushtaq (Islamabad, Pakistan)
G. P. Nagy (Szeged, Hungary)
J. Neggers (Alabama, USA)
J. D. Phillips (Michigan, USA)
J. D. H. Smith (Iowa, USA)
P. N. Syrbu (Chisinau, Moldova)
V. S. Trokhimenko (passed away 21 November 2020)
A. A. Ungar (North Dakota, USA)
I. M. Wanless (Melbourne, Australia)