APA (7th ed.) Citation

Kramer, K. U., Green, P. S., & Götz, E. (1990). Pteridophytes and gymnosperms. Springer-Verlag.

Chicago Style (17th ed.) Citation

Kramer, Karl Ulrich, P. S. Green, and Erich Götz. Pteridophytes and Gymnosperms. Berlin ; New York: Springer-Verlag, 1990.

MLA (9th ed.) Citation

Kramer, Karl Ulrich, et al. Pteridophytes and Gymnosperms. Springer-Verlag, 1990.