Complex sentence: He studied under Vasily Beliaev, Gugo Zaleman, Kuzma Petrov-Vodkin, and Vasily Shukhayev; among his teachers, the most important was Petrov-Vodkin, with his dimensional system of painting design and correlation of colour and form.
Split into simpler sentences: He studied under Vasily Beliaev, Gugo Zaleman, Kuzma Petrov-Vodkin, and Vasily Shukhayev. Among his teachers the most important was Kuzma Petrov-Vodkin with his dimensional system of painting design and correlation of colour and form.