A Theoretical and Experimental Study of the Symmetric Rank-One Update. - Humaid Khalfan; Richard H. Byrd; Robert B. Schnabel (SIAM J. Optim., 1993)

Analysis of a Symmetric Rank-One Trust Region Method. - Richard H. Byrd; Humaid Khalfan; Robert B. Schnabel (SIAM J. Optim., 1996)

Wide interval for efficient self-scaling quasi-Newton algorithms. - Mehiddin Al-Baali; Humaid Khalfan (Optim. Methods Softw., 2005)

A combined class of self-scaling and modified quasi-Newton methods. - Mehiddin Al-Baali; Humaid Khalfan (Comput. Optim. Appl., 2012)