Lilien et al. 2002 Lilien, G.; Morrison, P.D.; Searls, K.; Sonnack, M.; Von Hippel, E. (2002), "Performance Assessment of the Lead User Generation Process for New Product Development", Management Science, 48 (8): 1042–59, doi:10.1287/mnsc.48.8.1042.171, JSTOR822674
Lilien et al. 2002 Lilien, G.; Morrison, P.D.; Searls, K.; Sonnack, M.; Von Hippel, E. (2002), "Performance Assessment of the Lead User Generation Process for New Product Development", Management Science, 48 (8): 1042–59, doi:10.1287/mnsc.48.8.1042.171, JSTOR822674