APA (7th ed.) Citation

Erkama, T. (1973). Group actions and extension problems for maps of balls. Suomalainen Tiedeakatemia.

Chicago Style (17th ed.) Citation

Erkama, Timo. Group Actions and Extension Problems for Maps of Balls. Helsinki: Suomalainen Tiedeakatemia, 1973.

MLA (9th ed.) Citation

Erkama, Timo. Group Actions and Extension Problems for Maps of Balls. Suomalainen Tiedeakatemia, 1973.

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