APA (7th ed.) Citation

Behnke, J. M., Ketmer, A. E., & Lewis, J. W. (1991). Heligmosmoides polygyrus or Nematospiroides dubius? Elsevier.

Chicago Style (17th ed.) Citation

Behnke, Jerzy M., Anne E. Ketmer, and John W. Lewis. Heligmosmoides Polygyrus or Nematospiroides Dubius? Elsevier, 1991.

MLA (9th ed.) Citation

Behnke, Jerzy M., et al. Heligmosmoides Polygyrus or Nematospiroides Dubius? Elsevier, 1991.