Vogeler, Heinrich, 1872-1942. Annunciation to the Shepherds, from Art in the Christian Tradition, a project of the Vanderbilt Divinity Library, Nashville, TN. http://diglib.library.vanderbilt.edu/act-imagelink.pl?RC=56750 [retrieved December 24, 2018]. Original source: https://commons.wikimedia.org/wiki/File:Heinrich_Vogeler_Verk%C3%BCndigung_an_die_Hirten_1902.jpg.
