@book{Mayer+2020,
url = {https://doi.org/10.3790/9783428471904},
title = {Die Zusage nach der Abgabenordnung 1977},
title = {},
author = {Gerd Mayer},
publisher = {Duncker & Humblot},
address = {},
doi = {doi:10.3790/9783428471904},
isbn = {9783428471904},
year = {1991},
lastchecked = {2020}
}