@article{BuesingStiller2023a,
	author = {C. B\"{u}sing and S. Stiller},
	title = {Line planning, path constrained network flow and inapproximability},
	journal = {Networks},
	year = {2011},
	number = {1},
	pages = {106–113},
	volume = {57},
	month = {Jan},
	doi = {10.1002/net.20386}
}