Cite

APA
Chu, M. T., Diele, F., Plemmons, R., & Ragni, S. (2004). Optimality, computation, and interpretation of nonnegative matrix factorizations, 1–18.

Chicago/Turabian
Chu, M. T., F. Diele, R. Plemmons, and Stefania Ragni. “Optimality, Computation, and Interpretation of Nonnegative Matrix Factorizations” (December 1, 2004): 1–18.

MLA
Chu, M. T., et al. Optimality, Computation, and Interpretation of Nonnegative Matrix Factorizations. Dec. 2004, pp. 1–18.