APA

westerman g. v., Rosenthal H., . (1964). opera guide. new york: E.P. dutton & co.

Chicago

westerman gerhart von, Rosenthal Harold, . 1964. opera guide. new york: E.P. dutton & co.

Harvard

westerman g. v., Rosenthal H., . (1964). opera guide. new york: E.P. dutton & co.

MLA

westerman gerhart von, Rosenthal Harold, . opera guide. new york: E.P. dutton & co. 1964.