Kristjansson, Trausti T. ; Culotta, Aron ; Viola, Paul A. ; McCallum, Andrew ; McGuinness, Deborah L. (Bearb.) ; Ferguson, George (Bearb.): Interactive Information Extraction with Constrained Conditional Random Fields.. In: AAAI : AAAI Press/The MIT Press, 2004. - ISBN 0-262-51183-5, S. 412--418