@article{article161c18ec,
title   = {A matrix method for quasinormal modes: Schwarzschild black holes in asymptotically flat and (anti-) de Sitter spacetimes},
author = {Lin, Kai and Qian, Wei-liang},
year = {2017},
doi = {10.1088/1361-6382/aa6643},
journal   = {Classical and Quantum Gravity}
}