TY - JOUR AU - Gerhardt, Hans-Detlef TI - The beginning of a mathematical simulation theory JO - Kybernetika PY - 1977 SP - EP - 332 VL - 13 IS - 5 PB - mathdoc UR - http://geodesic.mathdoc.fr/item/KYB_1977__13_5_a1/ LA - en ID - KYB_1977__13_5_a1 ER -