Κοντογιάννη Π., Κοντογιάννη Ν. and Τσαμίτα Ι. 2020. Relationship between self-determination and stage of change of physical activity behavior of Greek students. Psychology: the Journal of the Hellenic Psychological Society. 17, 1 (Oct. 2020), 52–70. DOI:https://doi.org/10.12681/psy_hps.23754.