APA (7th ed.) Citation

Morales, J. L., & Nocedal, J. Algorithm 809: PREQN: Fortran 77 subroutines for preconditioning the conjugate gradient method. ACM transactions on mathematical software..

Chicago Style (17th ed.) Citation

Morales, José Luis, and Jorge Nocedal. "Algorithm 809: PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method." ACM Transactions on Mathematical Software. .

MLA (9th ed.) Citation

Morales, José Luis, and Jorge Nocedal. "Algorithm 809: PREQN: Fortran 77 Subroutines for Preconditioning the Conjugate Gradient Method." ACM Transactions on Mathematical Software., .