@book {9783956230295, 
	title = "30 Minuten Willenskraft",
	author = "Willmann, Hans-Georg",
	isbn = "9783956230295",
	year = "2013",
	edition = "1",
	keywords = "Motivation, Persönlichkeit, Wille, Persönliche Entwicklung, Willenskraft, Willensstärke, Lebensführung, Lebenshilfe, Stärken, starker Wille, Durchhaltevermögen",
	url = "http://www.content-select.com/index.php?id=bib_view&ean=9783956230295",
	url = "https://content-select.com/de/portal/media/view/562a013a-5a9c-41f6-baa8-191fb0dd2d03",
	publisher = "GABAL",
	language = "ger",
}