@article{01375587, title = {Polytypic functions over nested datatypes.}, journal = {Discrete Mathematics and Theoretical Computer Science. DMTCS [electronic only]}, volume = {3}, year = {1999}, pages = {193-214}, zbl = {0947.68031}, language = {en}, url = {http://dml.mathdoc.fr/item/01375587} }
Hinze, Ralf. Polytypic functions over nested datatypes.. Discrete Mathematics and Theoretical Computer Science. DMTCS [electronic only], Tome 3 (1999) pp. 193-214. http://gdmltest.u-ga.fr/item/01375587/