@inproceedings{inproceedingsc311e516,
title   = {Combining unigrams and bigrams in semi-supervised text classification},
author = {Braga, Ígor Assis and Monard, Maria Carolina and Matsubara, Edson Takashi},
year = {2009},
publisher = {APPIA},
booktitle   = {Portuguese Conference on Artificial Intelligence - EPIA}
}