Luck, L., List, H., Middell, G., & Hybler, Z. (1990). English step by step: English for beginners and an elementary refresher course, English for intermediate learners, English for advanced learners and scientiests (8., unveränd. Aufl.). Verlag Enzyklopädie.
Chicago-Zitierstil (17. Ausg.)Luck, Lydia, Horst List, Gudrun Middell, und Zdenek Hybler. English Step by Step: English for Beginners and an Elementary Refresher Course, English for Intermediate Learners, English for Advanced Learners and Scientiests. 8., unveränd. Aufl. Leipzig: Verlag Enzyklopädie, 1990.
MLA-Zitierstil (8. Ausg.)Luck, Lydia, et al. English Step by Step: English for Beginners and an Elementary Refresher Course, English for Intermediate Learners, English for Advanced Learners and Scientiests. 8., unveränd. Aufl. Verlag Enzyklopädie, 1990.