@inbook {BHI01,
	title = {Heuristics for the {PNS} problem},
	booktitle = {Optimization theory: Recent development from M{\'a}trah{\'a}za},
	year = {2001},
	pages = {1-18},
	author = {Z. Bl{\'a}zsik and Cs. Holl{\'o} and Cs. Imreh and Z. Kov{\'a}cs}
}
@article {BHI00,
	title = {On bottleneck and k-sum versions of the Process Network Synthesis problems},
	journal = {Novi Sad Journal of Mathematics},
	volume = {30},
	number = {3},
	year = {2000},
	pages = {11-19},
	author = {Z. Bl{\'a}zsik and Cs. Holl{\'o} and B. Imreh and Cs. Imreh and Z. Kov{\'a}cs}
}
@article {BHI00a,
	title = {On a well solvable class of the {PNS} problem},
	journal = {Novi Sad Journal of Mathematics},
	volume = {30},
	number = {3},
	year = {2000},
	pages = {21-30},
	author = {Z. Bl{\'a}zsik and Cs. Holl{\'o} and B. Imreh and Cs. Imreh and Z. Kov{\'a}cs}
}
@article {HBI99,
	title = {On a Merging Reduction of the Process Network Synthesis Problem},
	journal = {Acta Cybernetica},
	volume = {14},
	year = {1999},
	pages = {251-261},
	author = {Cs. Holl{\'o} and Z. Bl{\'a}zsik and Cs. Imreh and Z. Kov{\'a}cs}
}
