1. Statistical Analysis with Missing Data;Little,2002
2. L. Candillier, K. Jack, F. Fessant, F. Meyer, State-of-the-Art Recommender Systems, Information Science Publishing, 2008, pp. 1–22 (Chapter 1).
3. S. Funk, Netflix update: try this at home, 〈http://sifter.org/∼simon/journal/20061211.html〉 (2006).
4. Missing value estimation methods for DNA microarrays;Troyanskaya;Bioinformatics,2001
5. J. Scheffer, Dealing with missing data, in: Research Letters in the Information and Mathematical Sciences, 2002, pp. 153–160.