Carlborg, Frank W.
Scoott, Foresman, 1968
Buku Teks SO
Walpole, Ronald E.
Macmillan, 1968
Buku Teks SO
Sigel, Andrew F.
John Wiley & Sons, 1996
Buku Teks SO
Mood, Alexander McFarlane, 1913-
McGraw-Hill , 1974
Buku Teks SO
Mood, Alexander McFarlane, 1913-
McGraw-Hill, 1963
Buku Teks SO