Kachigan, Sam Kash, author
Radius Press, 1991
Buku Teks
David J. Bartholomew ... [et.al]
CRC Press, Taylor & Francis Group, 2008
Buku Teks
Dunteman, George Henry
Sage Publications, 1984
Buku Teks
Johnson, Richard A., author
Pearson Education International, 2007
Buku Teks
edited by Vic Barnett
John Wiley & Sons, 1981
Buku Teks