Collective Cross-Document Relation Extraction Without Labelled Data, Limin Yao, Sebastian Riedel and Andrew McCallum, Proceedings of the Conference on Empirical methods in natural language processing (EMNLP '10) 2010 [pdf]
@inproceedings{yao10collective,
    author={Limin Yao and Sebastian Riedel and Andrew McCallum}, 
    title={Collective Cross-Document Relation Extraction Without Labelled Data}, 
    bdsk-url-1={http://www.cs.umass.edu/~lmyao/papers/relation-emnlp10.pdf}, 
    booktitle={Proceedings of the Conference on Empirical methods in natural language processing (EMNLP '10)}, 
    year={2010}, 
}