Ulrich's international periodicals directory 1992-1993 : volume 1
R.R. Bowker, 1992
Buku Referensi
Ulrich's international periodicals directory 1990-1991 : volume 1
R. R. Bowker Company, 1990
Buku Referensi
Ulrich's international periodicals directory 1991-1992 : volume 2
R.R. Bowker, 1991
Buku Referensi
Ulrich's international periodicals directory 1991-1992 : volume 3
R.R. Bowker, 1991
Buku Referensi
Ulrich's international periodicals directory 1992-1993 : volume 2
R.R. Bowker, 1992
Buku Referensi