American Society of Civil Engineers, 1987
Buku Referensi
Balje, O. E., author
Wiley, 1981
Buku Referensi
Wilson, Billie Ann, author
Pearson Education, 2003
Multimedia
Perry, Anne Griffin, author
Mosby, 2007
Buku Teks
Whitfield, John, author
EPA Press, 1995
Buku Referensi