en.wikipedia.org/wiki/Farewell_of_Slavianka

The infobox dates adoption to 1937, but Tambov’s own regional reference source gives a later legal timeline.

According to the Tambov Encyclopedia (an official project supported by the Government of Tambov Oblast), the anthem of Tambov Oblast was:

• established under the regional law on official symbols on 14 September 2001;
• approved and regulated by the law "On the Anthem of Tambov Oblast" on 24 May 2002;
• and its text (lyrics by A. Mitrofanov) was approved in the wording of a law dated 27 February 2004.

So the article’s adoption date of 1937 is not correct for the regional anthem. 1937 is the year Tambov Oblast was created, not the year its anthem was officially adopted.

This line conflates the date of the music with the date of the lyrics.

Reliable Russian coverage of the march’s history states that while Vasily Agapkin composed "Farewell of Slavianka" in 1912, the first text set to the melody appeared in 1914 and its author is unknown. Separately, the well-known Soviet-era words by Arkady Fedotov were written much later, in 1965.

So labeling the lyrics as dating to 1912 is inaccurate: 1912 is the composition date of the march, not the date of the earliest known lyrics.