@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},
} 

@ARTICLE{
author={Balinska KT,Simic Slobodan K},
year={2001},
title={The nonregular, bipartite, integral graphs with maximum degree 4. Part I: basic properties},
journal={DISCRETE MATHEMATICS},
volume={236},
number={1-3},
pages={13-24},
document_type={Article},
}