Ph. Audra (France)
R. Bernasconi (Switzerland)
P. Bosak (Czech Rep.)
J. Calaforra Chordi (Spain)
S.A. Craven (S.Africa)
C.A. Hill (USA)
A. Klimchouk (Ukraine)
A. Kranjc (Slovenia)
S.E. Lauritzen (Norway)
D. Lowe (UK)
F. Nader (Lebanon)
D. Northrup (USA)
M. Pulina (Poland)
Y. Quinif (Belgium)
T.R. Shaw (UK)
A. Tyc (Poland)
H. Trimmel (Austria)
G. Veni (USA)
Special cooperation and joint publications with Speleogenesis