Smarandache, Florentin, author
Hexis, 2005
Buku Teks
Carnap, Rudolf, author
Dover Publications, 1958
Buku Teks
Copi, Irving M., author
Prentice-Hall, 1979
Buku Teks
Dalen, Dirk van, author
Springer-Verlag, 1994
Buku Teks
Standley, Gerald B., author
Houghton Mifflin, 1971
Buku Teks