@article{hinze-2002-polytypic, title={Polytypic values possess polykinded types}, volume={43}, ISSN={0167-6423}, url={http://dx.doi.org/10.1016/s0167-6423(02)00025-4}, DOI={10.1016/s0167-6423(02)00025-4}, number={2-3}, journal={Science of Computer Programming}, publisher={Elsevier BV}, author={Hinze, Ralf}, year={2002}, month=May, pages={129–159} }