Ben-Chai, David, author
Sense, 2012
eBooks
Garstens, Helen L., author
Macmillan, 1969
Buku Teks SO
Phares Odaffer, Randall Charles, Thomas Cooney, John Dossey, Jane Schielack
Pearson Addison Wesley, 2008
Buku Teks SO
Hinton, Gertrude D. M., author
Fearon Publ., 1969
Buku Teks SO
Devine, Donald F., author
John Wiley & Sons, 1983
Buku Teks