Tom M. Apostol, Mamikon A. Mnatsakanian. A New Look at Surfaces of Constant Curvature. The American Mathematical Monthly, 123(5):439-447, 2016. [doi]
@article{ApostolM16,
title = {A New Look at Surfaces of Constant Curvature},
author = {Tom M. Apostol and Mamikon A. Mnatsakanian},
year = {2016},
url = {https://www.tandfonline.com/doi/abs/10.4169/amer.math.monthly.123.5.439},
researchr = {https://researchr.org/publication/ApostolM16},
cites = {0},
citedby = {0},
journal = {The American Mathematical Monthly},
volume = {123},
number = {5},
pages = {439-447},
}