“The Ecclesiola in the Utrecht Castellum. Architectural-Historical Interpretation of the Remnants of the Heilig-Kruiskapel”. Bulletin KNOB 93, no. 4-5 (September 1, 1994): 150–161. Accessed April 21, 2026. https://bulletin.knob.nl/index.php/knob/article/view/Rijntjes150.