Aufschnaiter, S. v. et al. (1989): Play Orientation in Physics Education.

Aufschnaiter, S. v. & Schwedes, H. (1989). Play Orientation in Physics Education.. Science Education, 73(4), 467–479.@article{schwedesvonaufschnaiter1989, title={Play Orientation in Physics Education.}, author={Stefan von Aufschnaiter and Hannelore Schwedes}, year={1989}, journal={Science Education}, volume={73}, number={4}, pages={467--479} }