http://www.google.com/search?q=%22Enhancing+Relation+Extraction+by+Eliciting+Selectional+Constraint+Features+from+Wikipedia%22&num=100&hl=en&safe=off&rlz=1B3GGGL_enDE236DE236&filter=0

the first hit is www.springerlink.com/index/u80531830v34k784.pdf which leads to a for-payment site as long as you are not already having a subscription via your IP address...