Hierarchical relationships in bibliographic descriptions : INTERMARC Software-subgroup seminar 4 : Library systems seminar Essen 25 March-27 March 1981 /
Bonness, E.
Helal, A. H.(Ahmed H.)
Weiss, J. W.(Joachim W.)
Library systems seminar(1981 :Essen, Germany)
INTERMARC Software-Subgroup Seminar(4th :1981 :Essen, Germany)
Essen : Gesamthochschulbibliothek Essen,
1982.
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