Andrew J Sommese & Charles W Wampler, Ii 
Numerical Solution Of Systems Of Polynomials Arising In Engineering And Science, The [PDF ebook] 

Written by the founders of the new and expanding field of numerical algebraic geometry, this is the first book that uses an algebraic-geometric approach to the numerical solution of polynomial systems and also the first one to treat numerical methods for finding positive dimensional solution sets. The text covers the full theory from methods developed for isolated solutions in the 1980’s to the most recent research on positive dimensional sets.