APA (7th ed.) Citation

Fursiak, Y. A. (2013). Fast-growing sunspot groups AR1618, AR1619, AR1620, AR1640 and their features.

Chicago Style (17th ed.) Citation

Fursiak, Yu. A. Fast-growing Sunspot Groups AR1618, AR1619, AR1620, AR1640 and Their Features. 2013.

MLA (8th ed.) Citation

Fursiak, Yu. A. Fast-growing Sunspot Groups AR1618, AR1619, AR1620, AR1640 and Their Features. 2013.

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