@book{80,
	author = {Schwenn, Otto and Tischner, Bruno},
	title = {Praktisches Maschinenzeichnen},
	publisher = {Edmund Herrmann},
	year = {1923},
	address = {Berlin},
	edition = {2. Auflage},
	note = {In Fraktur},
	url = {https://d-nb.info/365604569/04}
}