Hedegaard, M., Hakkarainen, P., & Engestrom, Y. (1984). Learning and teaching on a scientific basis: Methodological and Epistemological aspects of the activity theory of learning and teaching. Psykologisk Institut.
Lua i Stíl Chicago (17ú heag.)Hedegaard, Mariane, Pentti Hakkarainen, agus Yrijo Engestrom. Learning and Teaching on a Scientific Basis: Methodological and Epistemological Aspects of the Activity Theory of Learning and Teaching. Dinamarca: Psykologisk Institut, 1984.
Lua MLA (9ú heag.)Hedegaard, Mariane, et al. Learning and Teaching on a Scientific Basis: Methodological and Epistemological Aspects of the Activity Theory of Learning and Teaching. Psykologisk Institut, 1984.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.