APA (7th ed.) Citation

ScienceDirect (Online service), Szabo, M. E., & Gentzen, G. (1969). The collected papers of Gerhard Gentzen. North-Holland.

Chicago Style (17th ed.) Citation

ScienceDirect (Online service), M. E. Szabo, and Gerhard Gentzen. The Collected Papers of Gerhard Gentzen. Amsterdam: North-Holland, 1969.

MLA (9th ed.) Citation

ScienceDirect (Online service), et al. The Collected Papers of Gerhard Gentzen. North-Holland, 1969.

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