A bibliographic reference is a description of some publication that uniquely identifies it, providing the information needed to retrieve the associated document. A reference is distinguished from a citation, which occurs in the body of a document and points to a reference. Note that references are distinguished from documents as well.The information associated with a reference is contained in data fields, which are binary relations (often unary functions).
A reference should at least contain information about the author, title, and year. (Since there are exceptions, that constraint is associated with a specialization of this class.) .
(Subclass-Partition Biblio-Thing (Setof Agent Timepoint Document Reference Conference)) (=> (Ref.Author $X $Y) (Reference $X)) (=> (Ref.Title $X $Y) (Reference $X)) (=> (Ref.Booktitle $X $Y) (Reference $X)) (=> (Ref.Year $X $Y) (Reference $X)) (=> (Ref.Periodical $X $Y) (Reference $X)) (=> (Ref.Notes $X $Y) (Reference $X)) (=> (Ref.Abstract $X $Y) (Reference $X)) (=> (Ref.Keywords $X $Y) (Reference $X)) (=> (Ref.Labels $X $Y) (Reference $X)) (=> (Ref.Secondary-Author $X $Y) (Reference $X)) (=> (Ref.Tertiary-Author $X $Y) (Reference $X)) (=> (Ref.Secondary-Title $X $Y) (Reference $X)) (=> (Ref.Address $X $Y) (Reference $X)) (=> (Ref.Organization $X $Y) (Reference $X)) (=> (Ref.Publisher $X $Y) (Reference $X)) (=> (Ref.Number-Of-Volumes $X $Y) (Reference $X)) (=> (Ref.Edition $X $Y) (Reference $X))