1956: Vol. 11, No. 6, 11 1958: Vol. 13, No. 12 1963: Vol. 18, No. 2, 9, 11 1965: Vol. 20, No. 1-12 1966: Vol. 21, No. 1-12 1967: Vol. 22, No. 1-6, 8-12 1968: Vol. 23, No. 2-3, 5-12 1969: Vol. 24, No. 1-2, 4-12 1970: Vol. 25, No. 1-3, 5-12 1971: Vol. 26, No. 1-12 1972: Vol. 27, No. 1-2, 4-12 1973: Vol. 28, No. 1-12 1974: Vol. 29, No. 1-12 1975: Vol. 30, No. 1-12 1976: Vol. 31, No. 1-12 1977: Vol. 32, No. 1-6, 8-12 1978: Vol. 33, No. 1-12 1979: Vol. 34, No. 1-12 1980: Vol. 35, No. 1-12 1981: Vol. 36, No. 1, 3-6, 8-12 1982: Vol. 37, No. 2-12 1983: Vol. 38, No. 1-12 1984: Vol. 39, No. 1-10, 12 1985: Vol. 40, No. 5, 7-12 1986: Vol. 41, No. 1-12 1987: Vol. 42, No. 1-12 1988: Vol. 43, No. 1-12 1989: Vol. 44, No. 1-12 1990: Vol. 45, No. 1-12 1991: Vol. 46, No. 1-7, 9-12 1992: Vol. 47, No. 1 1994: Vol. 49, No. 574-585 1995: Vol. 50, No. 587-596 1996: Vol. 51, No. 597-605 1997: Vol. 52, No. 606, 608-613 (October) 1998: Vol. 53, No. 616-626 1999: Vol. 54, No. 627-637 2000: Vol. 55, No. 638-645, 647-648 2001: Vol. 56, No. 649