Calkins, R. G. (1998). Medieval architecture in western europe: From a.d. 300 to 1500. Oxford unversity.
Chicago-viite (17. p.)Calkins, Robert G. Medieval Architecture in Western Europe: From A.d. 300 to 1500. New York: Oxford unversity, 1998.
MLA-viite (9. p.)Calkins, Robert G. Medieval Architecture in Western Europe: From A.d. 300 to 1500. Oxford unversity, 1998.
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