Xingping Sun. Strictly positive definite functions on the unit circle. Math. Comput., 74(250):709-721, 2005. [doi]
@article{Sun05-1,
title = {Strictly positive definite functions on the unit circle},
author = {Xingping Sun},
year = {2005},
doi = {10.1090/S0025-5718-04-01668-0},
url = {http://dx.doi.org/10.1090/S0025-5718-04-01668-0},
researchr = {https://researchr.org/publication/Sun05-1},
cites = {0},
citedby = {0},
journal = {Math. Comput.},
volume = {74},
number = {250},
pages = {709-721},
}