found: Rossini, G. Guglielmo Tell [SR] c1980 (a.e.) labels (Ambrosian Opera Chorus)
found: Bellini, V. Puritane [SR] 1980?: label (Opernyĭ khor "Ambrozian")
found: New Grove: v. 11, p. 191 (Ambrosian Singers; choir founded in 1952 by John McCarthy, primarily to perform medieval and Renaissance works; in 1956, six members formed the Ambrosian Consort, specializing in Renaissance music; the Ambrosian Opera Chorus grew out of the original organization)
found: Music. Am., Int. dir. perform. arts, 1998: p. 722 (Ambrosian Opera Chorus; Ambrosian Singers [listed together])