@article{articlebc64bfc8,
title   = {Evolution of active galactic nuclei broad-line region clouds: low-and high-ionization lines},
author = {Gonçalves, D. R. and Friaça, Amâncio César Santos and Jatenco-Pereira, Vera},
year = {2001},
doi = {10.1046/j.1365-8711.2001.04875.x},
journal   = {Monthly Notices of the Royal Astronomical Society}
}