Canadian Music Trades Journal, February 1917, p. 64: "The Mozart Piano Co., Ltd., was incorporated in 1909 with a capitalization of $10,000 and in 1912 built the factory now occupied at 94 to 110 Munro Street (Toronto). The factory output, from the commencement, has been largely taken by Heintzman & Co. The firm is also making a line of talking machines."
Canadian Music Trades Journal, February 1917, p. 64: "The National Piano Co. will take the output of the Mozart Piano Co., Ltd in which concern a substantial interest has been taken."
Canadian Music Trades Journal, September 1917, p. 63: "The line of National phonographs is manufactured by the Mozart Piano Co., Ltd, which is controlled by the National Piano Co., Ltd., [266-268 Yonge Street, Toronto]."
Talking Machine World
, March 1917, p.6. Toronto Trade. The talking machines were manufactured by the Mozart Piano Company which was controlled by the National Piano Company.
Toronto Daily Star
, November 18, 1920 - National "The Most Delightful Phonograph in the World".