APA (7th ed.) Citation

Schäfer, G. (1998). Friedrich Engels . builder of closed systems?

Chicago Style (17th ed.) Citation

Schäfer, Gert. Friedrich Engels . Builder of Closed Systems? 1998.

MLA (8th ed.) Citation

Schäfer, Gert. Friedrich Engels . Builder of Closed Systems? 1998.

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