Occupational hazards.

v.2 (1939); v.3; v.4; v.35 1973 Jan-Jun; v.35 1973 Jul-Dec; v.36 1974 Jan-Jun; v.36 1974 Jul-Dec; v.37 1975 Jan-Jun; v.37 1975 Jul-Dec; v.38 1976 Jan-Jun; v.38 1976 Jul-Dec; v.39 1977 Jan-Jun; v.39 1977 Jul-Dec; v.40 1978 Jan-May; v.40 1978 Jul-Dec; v.41 1979 Jan-Jun; v.41 1979 Jul-Dec; v.42 1980 Jan-Jun; v.42 1980 Jul-Dec; v.43 1981 Jan-Jun; v.43 1981 Jul-Dec; v.44 1982 Jan-Jun; v.44 1982 Jul-Nov; v.45 1983 Jul-Dec; v.46 1984 Jan-Jun; v.46 1984 Jul-Dec; v.47 1985 Jan-Jun; v.47 1985 Jul-Dec; v.48 1986 Jan-Jun; v.48 1986 Jul-Dec; v.49 1987 Jan-Jun; v.49 1987 Jul-Dec; v.50 1988 Jan-Jun; v.50 1988 Jul-Dec; v.51 1989 Jan-Jun; v.51 1989 Jul-Dec; v.52 1990 Jan-Jun; v.52 1990 Jul-Dec; v.53 1991 Jan-Jun; v.53 1991 Jul-Dec; v.54 1992 Jan-Jun; v.54 1992 Jul-Dec; v.55 1993 Jan-Jun; v.56 1994 Jan-Jun; v.57 1995 Jan-Jun; v.57 1995 Jul-Dec; v.58 1996 Jan-Jun; v.58 1996 Jul-Dec; v.59 1997 Jan-Jun; v.59 1997 Jul-Dec; v.60 1998 Jan-Jun; v.60 1998 Jul-Dec; v.61 1999 Jul-Dec; v.62 2000 Jan-Jun; v.62 2000 Jul-Dec; v.63 2001 Jan-Jun; v.63 2001 Jul-Dec; v.64 2002; v.65 2003; v.66 2004