The Grigorovich M-19 was a reconnaissance flying boat designed by Grigorovich in the late 1910s. The M-19 was a Grigorovich M-9 modified to be of the same size as the Grigorovich M-15. Assembly of the prototype was started in 1918, but the aircraft was not completed.[1]
^Shavrov, V.B. (1994). Istoriia konstruktskii samoletov v SSSR, 1938–1950 (in Russian) (gg. (3 izd.) ed.). Moscow: Mashinostroenie. pp. 292–293. ISBN978-5-217-00477-5.
Kulikov, Victor (December 1996). "Le fascinante histoire des hydravions de Dimitry Grigorovitch" [The Fascinating History of the Seaplanes of Dimitry Grigorovitch]. Avions: Toute l'aéronautique et son histoire (in French) (45): 20–33. ISSN1243-8650.