edited by. Herbert F. Lund
McGraw-Hill, 1971
Buku Referensi
edited by Herbert F. Lund
McGraw-Hill, 1971
Buku Referensi
Parr, E.A.
Butterworth-Heinemann, 1995
Buku Referensi
Badiru, Adedeji Bodunde, 1952-
Taylor & Francis, 2006
Buku Teks
Palmer, Marilyn
English Heritage, 2012
Buku Teks