@book{Häberle+2018,
url = {https://doi.org/},
title = {Different Paths toward Europe?},
title = {},
author = {Peter Häberle},
publisher = {Duncker & Humblot},
address = {},
doi = {doi:},
isbn = {9783428554188},
year = {2018},
lastchecked = {2018}
}