@InProceedings{ThomasH07, author = {Paul Thomas and David Hawking}, title = {Evaluating sampling methods for uncooperative collections}, booktitle = {Proceedings of ACM SIGIR 2007}, pages = {503--510}, location = {Amsterdam, Netherlands}, year = 2007, month = {July}, note = {\url{https://david-hawking.net/pubs/fp347-thomas.pdf}} }