Beshara, Tony, 1948- , author
American Management Association, 2008
eBooks
Martin, Carole, author
McGraw-Hill, 2012
Buku Teks
Fletcher, John, author
Duckworth, 1973
Buku Teks
Spradley, James P., author
Halt, Rinehart and Winston, 1979
Buku Teks
American Concrete Institute. Committee 317.
American Concrete Institute, 1965
Buku Referensi