@article{DBLP:journals/sLogica/Dzierzgowski98,
author = {Daniel Dzierzgowski},
title = {Finite Sets and Natural Numbers in Intuitionistic TT Without
Extensionality},
journal = {Studia Logica},
volume = {61},
number = {3},
year = {1998},
pages = {417-428},
ee = {http://dx.doi.org/10.1023/A:1005022208588},
bibsource = {DBLP, http://dblp.uni-trier.de}
}