BibTex format
@article{Ortega:2002:10.1016/S0167-6911(02)00212-8,
author = {Ortega, R and Astolfi, A and Barabanov, NE},
doi = {10.1016/S0167-6911(02)00212-8},
journal = {SYSTEMS & CONTROL LETTERS},
pages = {259--278},
title = {Nonlinear PI control of uncertain systems: an alternative to parameter adaptation},
url = {http://dx.doi.org/10.1016/S0167-6911(02)00212-8},
volume = {47},
year = {2002}
}