共 7 条
[3]
Kopal Z., 1941, ANN NY ACAD SCI, V41, P13
[4]
KOPAL Z, 1956, JODRELL BANK ANN, V1, P141
[5]
Oosterhoff P.T., 1933, B ASTRON I NETH, V7, P107
[6]
PEREK L, 1952, ASTR PUBL MASARYK U, V1, P17