19. The system of claim 13 , wherein the executable and operational data are further effective to cause the one or more processors to evaluate similarity of the candidate articles to the principal article by evaluating similarity of out-links of the principal article and the candidate articles.
19. The system of claim 13 , wherein the executable and operational data are further effective to cause the one or more processors to evaluate similarity of the candidate articles to the principal article by evaluating similarity of out-links of the principal article and the candidate articles. 21. The system of claim 19 , wherein the executable and operational data are further effective to cause the one or more processors to evaluate similarity of out-links of the principal article and the candidate articles by evaluating similarity of placement of the out-links of the principal article and the candidate articles.