Pernetta, John
George Philip, 1995
Buku Referensi
University of Technology Sydney
Lovell Johns , 1996
Buku Referensi
C.S. Hammond & Co. , 1960
Buku Referensi
James E Davis, colsultan
Graphic Learning,, 1978
Buku Referensi
George Phillip, 1981
Buku Referensi