TY - JOUR TI - Zprávy JO - Applications of Mathematics PY - 1973 SP - 140 VL - 18 IS - 2 UR - http://geodesic.mathdoc.fr/articles/10.21136/AM.1973.103462/ DO - 10.21136/AM.1973.103462 LA - cs ID - 10_21136_AM_1973_103462 ER -