@article{paperid:1026947,
author = {,  and Andrea Lodi and Afsharnejad, Zahra},
title = {Improving spectral bounds for clustering problems by Lagrangian relaxation},
journal = {International Transactions in Operational Research},
year = {2011},
volume = {10},
number = {18},
month = {June},
issn = {0969-6016},
pages = {647--661},
			numpages = {14},
keywords = {Minimum sum of squares; ratio association problem. optimazation},
}