@mastersthesis {Lange_2018,
	title = {Ground states and spectral properties in quantum field theories},
	year = {2018},
	school = {Friedrich-Schiller-University Jena},
	type = {phd},
	doi = {10.22032/dbt.35196},
	url = {https://www.db-thueringen.de/receive/dbt_mods_00035196},
	author = {Markus Lange}
}
