Beethoven, L. v., & Kail, R. (1980). World's favorite classic & romantic piano duets: For one piano-four hands by Beethoven ... [et al.]. Ashley Pub.
Čikaški stil citiranja (17. izdanje)Beethoven, Ludwig van, i Robert Kail. World's Favorite Classic & Romantic Piano Duets: For One Piano-four Hands by Beethoven ... [et Al.]. New Jersey: Ashley Pub, 1980.
MLA način citiranja (9. izdanje)Beethoven, Ludwig van, i Robert Kail. World's Favorite Classic & Romantic Piano Duets: For One Piano-four Hands by Beethoven ... [et Al.]. Ashley Pub, 1980.
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