Rozhko, Mikhail Viktorovich, Vladimir Anatolyevich Rubtzov, and Niyaz Kamilevich Gabdrakhmanov. 2017. “Positioning of the Republic of Mari El in Volga Federal District”. Revista Publicando 4 (13 (3): 905-15. https://revistapublicando.org/revista/index.php/crv/article/view/1015.