Kölner geographische Arbeiten.

no.1-5; no.6-8; no.6-7 1955; no.9-11; no.12-14; no.15-18; no.15-18 1963-1966; no.19-20; no.19-20 1967-1968; no.21-22; no.21-23 1969; no.23; no.24 1970; no.25-26 1971; no.25-27 1971-72; no.27-28 1972-1973; no.28; no.29-30; no.29-31 1973-1974; no.31; no.32-33; no.32-33 1975; no.34-35; no.34-36 1976-1978; no.36-38; no.37-39 1979-1981; no.39; no.40-42; no.40-41 1982; no.42-44 1982-1983; no.45-46 1984-1987; no.47-49 1987-1988; no.48 yr.1988; no.49 yr.1988; no.50-51 1989; no.52-53 1990; no.52 yr.1990; no.54-55 1991; no.54 yr.1991; no.56 1992; no.57-58 1993; no.59-60 1993; no.61-64 1994-1995; no.65-67 1995; no.68-70 1997-1998; no.71-72 1999; no.73-74 2000; no.75-76 2001-2002; no.77-78 2002; no.80-81 2003-2004; no.82 2004; no.83 2004; no.84-85 2004; no.86 2005; no.87 2007