Inference and Missing Data, Donald B. Rubin, 1976Biometrika, Vol. 63 (Biometrika Trust)DOI: 10.1093/biomet/63.3.581 - This foundational paper formally introduced the classification of missing data mechanisms (MCAR, MAR, MNAR) and laid the groundwork for modern missing data theory.
Statistical Analysis with Missing Data, Roderick J. A. Little and Donald B. Rubin, 2019 (John Wiley & Sons)DOI: 10.1002/9781119482260 - A comprehensive book that serves as the definitive reference for statistical methods for handling missing data, including detailed discussions of MCAR, MAR, and MNAR mechanisms.