For citations:

Petrochenkov D.A., Petrov A.V. Mineral composition and structural features of jewelry ammonites from mine OJSC «Mikhailovcement», Ryazan region. Proceedings of higher educational establishments. Geology and Exploration. 2019;(4):18-25. (In Russ.) https://doi.org/10.32454/0016-7762-2019-4-18-25