Implementing on O(/NM) Cardinality Matching Algorithm. - R. Bruce Mattingly; Nathan P. Ritchey (Network Flows And Matching, 1991)

The time path of the marginal cost of oil: The turning point and the subsequent upward drift. - Sten Thore; S. L. McDonald; R. Gonzalez; Nathan P. Ritchey; Timothy W. Ruefli; K. K. Sinha (Ann. Oper. Res., 1996)

Implementation Brief: Quality Assurance in Anatomic Pathology: Automated SNOMED Coding. - Kimbroe J. Carter; Suzanne Rinehart; Edward Kessler; Leonard P. Caccamo; Nathan P. Ritchey; Barbara A. Erickson; Frank Castro; Marcia D. Poggione (J. Am. Medical Informatics Assoc., 1996)