S. Zerr, O. Papapetrou, and E. Demidova. Proceeding of the 1st International Workshop on Privacy-Preserving IR: When Information Retrieval Meets Privacy and Security co-located with 37th Annual International ACM SIGIR conference, PIR@SIGIR 2014, Gold Coast, Australia, July 11, 2014., page 1--6. (2014)