Holdings
18.1978,4;6;7; 19.1979;4-6; 20.1980, 1-5; 21.1981 - 25.1985; 26.1986,1-4;5-8; 27.1987, 1-11; 28.1988,1-12; 29.1989,1-5; 7-12; 30.1990, 1-5; 7-12; 31.1991, 1-6; 8; 10-12; 32.1992,1-12; 33.1993,1-4; 6-9; 11-12; 34.1994,1-2; 4-12; 35.1995,1-12; 36.1996,1-2; 4-10; 37.1997, 1-9; 38.1998,3;5-6;8-10; 39.1999,2-4;8-10; 40.2000, 1-10;