https://katalog.hfmdd.de/Record/ai-49-aHR0cDovL2R4LmRvaS5vcmcvMTAuMjQ3OC92MTAzMDAtMDEyLTAwMTAtNQ Szombara, Stanisław:
Transformation of Areal Objects Into Linear Objects, Regarding the Map Scale. 2013. — .