APA (7th ed.) Citation

Ilchenko, Y., & Perelyhina, L. S. (2015). The Early History of Helicopter Design in Ukraine (late 19th – early 20th centuries).

Chicago Style (17th ed.) Citation

Ilchenko, Yu, and L. S. Perelyhina. The Early History of Helicopter Design in Ukraine (late 19th – Early 20th Centuries). 2015.

MLA (8th ed.) Citation

Ilchenko, Yu, and L. S. Perelyhina. The Early History of Helicopter Design in Ukraine (late 19th – Early 20th Centuries). 2015.

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