@ARTICLE{
author={de Abreu Nair MM,Balinska Krystyna T,Simic Slobodan K,Zwierzynski Krzysztof T},
year={2014},
title={More on Non-Regular Bipartite Integral Graphs with Maximum Degree 4 Not Having +/- 1 as Eigenvalues},
journal={APPLICABLE ANALYSIS AND DISCRETE MATHEMATICS},
volume={8},
number={1},
pages={123-154},
document_type={Article},
} 

@ARTICLE{
author={Balinska KT,Simic Slobodan K,Zwierzynski Krzysztof T},
year={2004},
title={Which non-regular bipartite integral graphs with maximum degree four do not have +/- 1 as eigenvalues?},
journal={DISCRETE MATHEMATICS},
volume={286},
number={1-2},
pages={15-24},
document_type={Article},
}