APA (7th ed.) Citation

Marino, A., & Murthy, M. K. V. (1989). Nonolinear variational problems. Longman.

Chicago Style (17th ed.) Citation

Marino, A., and M. K. V. Murthy. Nonolinear Variational Problems. Harlow, Essex England: Longman, 1989.

MLA (9th ed.) Citation

Marino, A., and M. K. V. Murthy. Nonolinear Variational Problems. Longman, 1989.