Here are some of the books and Research Publications on Recommendation Systems

Free & downloadable (Good introduction on Collaborative Filtering Recommendation) http://elehack.net/research/pubs/cf-survey/cf-survey.pdf

Other books are -

1. Recommender Systems - Introduction

2. Recommender Systems - Handbook

Here are some of the books and Research Publications on Recommendation Systems

Free & downloadable (Good introduction on Collaborative Filtering Recommendation) http://md.ekstrandom.net/research/pubs/cf-survey/

Other books are -

1. Recommender Systems - Introduction

2. Recommender Systems - Handbook