Valkenburg, Mac E. Van. creator text New Delhi Prentice Hall College Div 2010 3rd ed. monographic 571 p. ; Network Analysis. 621.3192VAL 0136110959 (hardcover) 9780136110958 (hardcover) http://www.amazon.com/exec/obidos/ASIN/0136110959/chopaconline-20 http://www.amazon.com/exec/obidos/ASIN/0136110959/chopaconline-20