Return on Quality at Chase Manhattan Bank. - Roland T. Rust; Timothy L. Keiningham; Stephen Clemens; Anthony Zahorik (Interfaces, 1999)

Invited Commentary - Net Promoter, Recommendations, and Business Performance: A Clarification on Morgan and Rego. - Timothy L. Keiningham; Lerzan Aksoy; Bruce Cooil; Tor Wallin Andreassen (Mark. Sci., 2008)