Reference books of ... :
an informal supplement to Guide to reference books, sixth edition.
APA Citation
Mudge, I. Gilbert., Winchell, C. M. (Constance Mabel). Reference books of ...: an informal supplement to Guide to reference books, sixth edition. Chicago, Ill.: American Library Association.
MLA Citation
Mudge, Isadore Gilbert, 1875-1957, and Constance M. (Constance Mabel) Winchell. Reference Books of ...: an Informal Supplement to Guide to Reference Books, Sixth Edition. Chicago, Ill.: American Library Association,
Warning: These citations may not always be complete (especially for serials).