NGS

National Geographic - 1989 Oct. - Vol. 176, No. 4.

National Geographic - 1988 August. - Vol. 173, No. 2.

National Geographic - 1977 March; April; July; Aug. (4 szám)

National Geographic - 1980 April; July; Nov. (3 szám)

National Geographic - 1968 July - 1970 Jan.; Oct. (3 szám)

National Geographic - 1975 March; Oct. - 1976 Jan. (3 szám)

National Geographic - 1977 March; April; July; Aug.; Nov. (5 szám)

National Geographic - 1978 Jan.; April; June (3 szám)

National Geographic - 1979 May; June; July; Aug.; Nov. (5 szám)

National Geographic - 1980 March; April; July; Aug.; Oct.; Nov. (6 szám)

National Geographic - 1981 July.; Sept.; Oct.; Dec. (4 szám)