1. Biggs JB, Telfer R (1987) The process of learning. Prentice-Hall, Sydney
2. Carnap R (1987) The confirmation of laws and theories. In: Janet A (ed) Scientific knowledge. Wadsworth Publishing Company, Kourany
3. Denzin NK, Lincoln YS (2001) The discipline and practice of qualitative research. In: Denzin NK, Lincoln YS (eds) Handbook of qualitative research. Sage Publications, London
4. Dimitrov V (2000) Discovering fuzziology. University of Western Sydney, Sydney
5. Gödel K (1932) Ein Spezialfall des Entscheidungsproblem der theoretischen Logik. Ergebnisse eines mathematischen Kolloquiums 2:27–28. Reprinted and translated in (Gödel, 1986, 130–235)