Lederer, Harald W.Harald W.Lederer2019-09-192015-07-131998https://fis.uni-bamberg.de/handle/uniba/38231engIllegal migration: why does it exist and what do we know about numbers and trends?workingpaperhttps://web.archive.org/web/20040521060731/http://www.uni-bamberg.de/~ba6ef3/pdf/efms_p19.pdf