Benedetto Intrigila, Richard Statman. Some results on extensionality in lambda calculus. Annals of Pure and Applied Logic, 132(2-3):109-125, 2005. [doi]
@article{IntrigilaS05,
title = {Some results on extensionality in lambda calculus},
author = {Benedetto Intrigila and Richard Statman},
year = {2005},
doi = {10.1016/j.apal.2003.05.001},
url = {http://dx.doi.org/10.1016/j.apal.2003.05.001},
researchr = {https://researchr.org/publication/IntrigilaS05},
cites = {0},
citedby = {0},
journal = {Annals of Pure and Applied Logic},
volume = {132},
number = {2-3},
pages = {109-125},
}