BartleyW.W.III (1984). The retreat to commitment (2nd ed., rev. and enlarged). La Salle: Open Court
2.
CopiI.M.CohenC. (1990). Introduction to logic (8th ed). New York: Macmillan
3.
NealeJ.M.LiebertR.M. (1986). Science and behavior: An introduction to methods of research (3rd ed.). Englewood Cliffs, New Jersey: Prentice-Hill
4.
SuppeF. (Ed.) (1974). The structure of scientific theories.Urbana: University of Illinois Press
5.
South African Journal of Sociology, (1991), 22(2), 33–58
6.
Van StadenF.VisserD. (1991). The South African Journal of Sociology during the eighties: An analysis of theoretical and empirical contributions. South African Journal of Sociology, 22(2), 33–43
7.
WeimerW.B. (1979). Notes on the methodology of scientific research.Hillsdale, New Jersey: Lawrence Erlbaum