Edmond Nadler. Nonnegativity of bivariate quadratic functions on a triangle. Computer Aided Geometric Design, 9(3):195-205, 1992. [doi]
@article{Nadler92,
title = {Nonnegativity of bivariate quadratic functions on a triangle},
author = {Edmond Nadler},
year = {1992},
doi = {10.1016/0167-8396(92)90017-J},
url = {http://dx.doi.org/10.1016/0167-8396(92)90017-J},
researchr = {https://researchr.org/publication/Nadler92},
cites = {0},
citedby = {0},
journal = {Computer Aided Geometric Design},
volume = {9},
number = {3},
pages = {195-205},
}