@inproceedings{143206,
 author = {Mads Tofte},
 title = {Principal signatures for higher-order program modules},
 booktitle = {Proceedings of the 19th ACM SIGPLAN-SIGACT symposium on Principles of programming languages},
 year = {1992},
 isbn = {0-89791-453-8},
 pages = {189--199},
 location = {Albuquerque, New Mexico, United States},
 doi = {http://doi.acm.org/10.1145/143165.143206},
 publisher = {ACM Press},
 }