BibTex format
@inproceedings{Tzimiropoulos:2011:10.1109/CVPRW.2011.5981809,
author = {Tzimiropoulos, G and Zafeiriou, S and Pantic, M},
doi = {10.1109/CVPRW.2011.5981809},
pages = {26--33},
title = {Sparse representations of image gradient orientations for visual recognition and tracking},
url = {http://dx.doi.org/10.1109/CVPRW.2011.5981809},
year = {2011}
}