Mark Allinson (편집.). 《Germany and Austria since 1814》. Routledge. 58쪽. Zentrum: Roman Catholic party which moved from the political centre to the right in the late 1920s.
jstor.org
David Blackbourn, "The Political Alignment of the Centre Party in Wilhelmine Germany: A Study of the Party's Emergence in Nineteenth-Century Württemberg," Historical Journal Vol. 18, No. 4 (Dec., 1975), pp. 821-850 in JSTOR
