1978=1978,3; 1979=1979,4; 1980=1980,3; 1981=1981,6; 1982=1982,4; 1983=1983,4; 1984=1984,4; 1985=1985,5; 1986=1986,5, 1987=1987,5; 1988=1988,4; 1989=1989,4; 1990=1990,4; 1991=1991,8; 1992=1992,3; 1993=1993,4; 1994=1994,3; 1995=1995,3; 1996=1996,4; 1997=1997,2; 1998=1998,4; 1999=1999,3; 2000=2000,2; 2001=2001,3; 2002=2002,3; 2003=2003,3; 2004=2004,2; 2006=2006,2; 2007=2007,2; 2008=2008,2; 2009=2009,3; 2010=2010,3; 2011=2011,4; 2012=2012,5; 2013=2013,3; 2014=2014,3; 2015=2015,3 von: Handwerkskammer Düsseldorf: Information, Dokumentation (ISSN: 0178-7012)