reference
1. ref.er.ence \'ref-*rn(t)s, 'ref-(*-)r*n(t)s\ n 1: the act of referring or consulting 2: a bearing on a matter : RELATION 3: something that refers : as 3a: ALLUSION, MENTION 3b: a sign or indication referring a reader to another passage or book 3c: consultation of sources of information 4: one referred to : as 4a: a person to whom inquiries as to character or ability can be made 4b: a statement of the qualifications of a person seeking employment or app ointment given by someone familiar with them 4c: a book or passage to which a reader is referred 4d: DENOTATION, MEANING 2. reference vt : to supply with references
Webster's English Dictionary