Singhs KS., Harban , author
LexisNexis, 2011
Buku Teks
compiled and edited by Harold Shepherd and Byron D. Sher
Foundation Press, 1960
Buku Teks
Stokes, McNeill, author
McGraw-Hill, 1977
Buku Teks
ASCE, 1991
Buku Teks
Collier, Keith, 1927-, author
Delmar, 1994
Buku Teks