found: Beatus, Saint, Presbyter of Liebana. Expositio im Apocalisim, 1992:commentary vol., p. 7, 1st sequence (Catedral de El Burgo de Osma)
found: Columbia Lippincott gazetteer of the world, 1952(Burgo de Osma, El, town in Soria province, N. Central Spain, in Old Castile, with 13th-century cathedral)
found: Enciclopedia universal ilustrada, [1907?]-c1930(Burgo de Osma (El))
found: El Burgo de Osma, 1997:p. 7 (in the province of Soria)
found: BGN gaz., Spain, 1961(El Burgo de Osma; ppl; 41°35ʹN, 3°04ʹW; in the province of Soria)