APA (7th ed.) Citation

Hetman, I. A., & Hetman, M. A. (2015). Electronic textbook as an important element in the system of distance education.

Chicago Style (17th ed.) Citation

Hetman, I. A., and M. A. Hetman. Electronic Textbook as an Important Element in the System of Distance Education. 2015.

MLA (8th ed.) Citation

Hetman, I. A., and M. A. Hetman. Electronic Textbook as an Important Element in the System of Distance Education. 2015.

Warning: These citations may not always be 100% accurate.