@inproceedings{PNMFICFE,
author = {Zhijian Yuan and Erkki Oja},
booktitle = {14th Scandinavian Conference on Image Analysis},
pages = {333-342},
publisher = {Springer},
title = {Projective nonnegative matrix factorization for image compression and feature extraction},
volume = {3540},
year = {2005},
}