Janssens R, Lang T, Vallejo A, Galinsky J, Plate A, Morgan K, Cabezudo E, Silvennoinen R, Coriu D, Badelita S, Irimia R, Anttonen M, Manninen RL, Schoefs E, Vandebroek M, Vanhellemont A, Delforge M, Stevens H, Simoens S, Huys I. Patient preferences for multiple myeloma treatments: a multinational qualitative study. Front Med (Lausanne). 2021 Jul 6;8:686165. doi: 10.3389/fmed.2021.686165
Parsley (Edwards) TL. Review of the phantom respondents: opinion surveys and political representation. J Off Stat. 1994;10(3):351-5.