Não informado. (1999). Open Praxis. International Council for Distance Education.
Chicago (17e ed.) BronvermeldingNão informado. Open Praxis. Cambridge, Inglaterra: International Council for Distance Education, 1999.
MLA (8e ed.) BronvermeldingNão informado. Open Praxis. International Council for Distance Education, 1999.
Let op: Deze citaties zijn niet altijd 100% accuraat.