Tchaikovsky, P. I. The Seasons. June: Barcarolle (Vremena goda. Iyun: Barkarola), 1918. For Piano Four Hands. Op. 37 bis, No. 6. Published by P. Jurgenson. In Russian.

Чайковский, П. И. Времена года. Июнь, Баркарола : Для фортепиано в четыре руки : Соч. 37 bis, № 6.
Москва : П. Юргенсон, 1918.
9 с. Мягкая издательская обложка, энциклопедический формат.
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Tchaikovsky, Pyotr Ilyich. The Seasons. June, Barcarolle : For piano four hands : Op. 37 bis, No. 6.
Moscow : P. Jurgenson, 1918.
9 pp. Soft publisher's cover, encyclopedic format. 

This 1918 musical edition is a fascinating historical artifact from a pivotal moment in Russian history. Published by the legendary P. Jurgenson firm during the first year of the Russian Civil War, it demonstrates the surprising continuity of classical music publishing amidst revolutionary upheaval. This specific volume presents a four-hand arrangement of the most iconic piece from Pyotr Ilyich Tchaikovsky’s celebrated cycle, "The Seasons" (Op. 37 bis).
This edition contains the sheet music for a four-hand piano arrangement of Barcarolle (June), part of the piano cycle The Seasons (Op. 37 bis), composed by Pyotr Ilyich Tchaikovsky (1840–1893) in 1875–1876 for the magazine Nouvelliste. The cycle comprises 12 characteristic pieces, each corresponding to a month, with Barcarolle (No. 6, G minor, Andante cantabile) evoking the lyrical, melancholic atmosphere of June through a swaying rhythm. The four-hand arrangement allows for a richer harmonic texture, distributing Tchaikovsky’s soulful G-minor melody and the "rowing" accompaniment across the full range of the keyboard, making it a staple of domestic music-making and pedagogical repertoire.
While the Jurgenson house was nationalized shortly after this printing, this 1918 edition retains the high engraving standards and aesthetic hallmarks of the late Imperial era. The "Barcarolle" remains one of Tchaikovsky's most evocative works, capturing the quietude and longing of a Russian summer evening.
For musicologists, piano duos, and collectors of Tchaikovskyana, this 1918 Jurgenson imprint is a rare bridge between the old world of Imperial Russian music and the nascent Soviet era. It stands as a testament to the enduring power of Tchaikovsky's lyricism during times of great social change.