@BOOK { Rsds2352,
title = {Incomplete Information: Rough Set Analysis}, 
series =  = {Studies in Fuzziness and Soft Computing, Vol. 13}, 
publisher = {Physica-Verlag}, 
address = {Heidelberg, Germany}, 
year = 1997, 
editor = {Orlowska, Ewa}, 
url = {http://www.springer.de}, 
isbn = {3-7908-1049-5}, 
keywords = {fuzzy logic, artificial intelligence, rough sets, incomplete information, }, 
}