DiTrapani J, Rockwood N, Jeon M. Explanatory IRT analysis using the SPIRT macro in SPSS. TQMP. 2018;14(2):81-98. doi: 10.20982/tqmp.14.2.p081
Suchdev PS, Ruth L, Obure A, Were V, Ochieng C, Ogange L, Owuor M, Ngure F, Quick R, Juliao P, Jung C, Teates K, Cruz K, Jefferds MED. Monitoring the marketing, distribution, and use of Sprinkles micronutrient powders in rural western Kenya. Food Nutr Bull. 2010 Jun;31(2 Suppl):S168-78. doi: 10.1177/15648265100312S209