Creating a Living Specification Using FIT Documents. - Prashant Gandhi; Nils Christian Haugen; Mike Hill; Richard Watt (AGILE, 2005)

An Empirical Study of Using Planning Poker for User Story Estimation. - Nils Christian Haugen (AGILE, 2006)

Combining Estimates with Planning Poker–An Empirical Study. - Kjetil Moløkken-Østvold; Nils Christian Haugen (ASWEC, 2007)

Using planning poker for combining expert estimates in software projects. - Kjetil Moløkken-Østvold; Nils Christian Haugen; Hans Christian Benestad (J. Syst. Softw., 2008)