Marco Riccardi. Categorical Pullbacks. Formalized Mathematics, 23(1):1-14, 2015. [doi]
@article{Riccardi15,
title = {Categorical Pullbacks},
author = {Marco Riccardi},
year = {2015},
url = {http://www.degruyter.com/view/j/forma.2015.23.issue-1/forma-2015-0001/forma-2015-0001.xml},
researchr = {https://researchr.org/publication/Riccardi15},
cites = {0},
citedby = {0},
journal = {Formalized Mathematics},
volume = {23},
number = {1},
pages = {1-14},
}