APA (7th ed.) Citation

Helfet, A. J., & Gruebel Lee, D. M. (1978). Disorders of the lumbar spine. Lippincott.

Chicago Style (17th ed.) Citation

Helfet, Arthur J., and David M. Gruebel Lee. Disorders of the Lumbar Spine. Philadelphia: Lippincott, 1978.

MLA (9th ed.) Citation

Helfet, Arthur J., and David M. Gruebel Lee. Disorders of the Lumbar Spine. Lippincott, 1978.