M. J. D. Powell, Malcolm A. Sabin. Piecewise Quadratic Approximations on Triangles. ACM Transactions on Mathematical Software, 3(4):316-325, 1977. [doi]
@article{PowellS77,
title = {Piecewise Quadratic Approximations on Triangles},
author = {M. J. D. Powell and Malcolm A. Sabin},
year = {1977},
doi = {10.1145/355759.355761},
url = {http://doi.acm.org/10.1145/355759.355761},
researchr = {https://researchr.org/publication/PowellS77},
cites = {0},
citedby = {0},
journal = {ACM Transactions on Mathematical Software},
volume = {3},
number = {4},
pages = {316-325},
}