Eells, Elsie Spicer
Robert M. McBride & Company, 1931
Buku Teks
Routledge, 2014
eBooks
Anabella Davila
Routledge, Taylor & Francis Group, 2009
Buku Teks
Hussey, Russell C., author
McGraw-Hill, 1947
Buku Teks
Hayden, Sally, author
AVedition, 2001
Buku Teks