The National Union Catalog [Text]. - London : Mansell.
Vol. 678 : Yandell, Lunsford Pitts - Yorick's skull / chairman G. R. Williams ; American Library Association. Resources and technical services division. - 1980. - 698 p. - ISBN 0-7201-1533-7
The National Union Catalog [Text]. - London : Mansell.
Vol. 677 : Wyoming. State geologist (N) - Yandell, Frederick Field / chairman G. R. Williams ; American Library Association. Resources and technical services division. - 1980. - 698 p. - ISBN 0-7201-1532-9