Holdings
1.1968,6; 7.1972,1-4; 8.1973,4-6; 10.1975,2-3u.7-8u.10; 11.1976,1-11; 12.1977,1-5u.10u.12; 13.1978,1u.4-5; 14.1979,1-2u.4u.6u.8-12; 15.1980,1-7u.11-12; 16.1981; 17.1982,1-10; 18.1983,1-4u.6-11; 19.1984,1-9u.12; 20.1985,1-3u.5-8u.10-12; 21.1986,1u.3-6u.8-12; 22.1987; 23.1988,2-6u.8-12; 24.1989 - 25.1990; 26.1991,1-8u.11-12; 27.1992 - 28.1993; 29.1994,1-8u.10-12; 30.1995,2-12; 31.1996,3-12; 32.1997 - 36.2001,2