Bray JW, Davis KL, Graver L, Schroeder D, Buck JA, Dilonardo J, Vandivort R. Mental health and substance abuse treatment utilization among individuals served by multiple public agencies in 3 states. J Behav Health Serv Res. 2005 Jan 1;32(3):282-93.
Parsley (Edwards) TL. Review of the phantom respondents: opinion surveys and political representation. J Off Stat. 1994;10(3):351-5.