Sandage, C.H.
Richard D. Irwin, 1961
Buku Teks
Sandage, C.H.
Richard D. Irwin, 1960
Buku Teks
Rotzoll, Kim B.
GRID Publishing, 1976
Buku Teks
Hotchkiss, George Burton, author
Alexander Hamilton Institute , 1961
Buku Teks
Wells, William D., author
Prentice-Hall, 2000
Buku Teks