APA (7th ed.) Citation

Heckmann, R. (1986). Manual for the ELL(2)-parser generator and tree generator generator.

Chicago Style (17th ed.) Citation

Heckmann, Reinhold. Manual for the ELL(2)-parser Generator and Tree Generator Generator. Saarbrücken, 1986.

MLA (9th ed.) Citation

Heckmann, Reinhold. Manual for the ELL(2)-parser Generator and Tree Generator Generator. 1986.

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