  Preliminary version of a contribution to the "Quantum Field Theory.
Non-Perturbative QFT" topical area of "Modern Encyclopedia of Mathematical
Physics" (SELECTA), eds. Aref'eva I, and Sternheimer D, Springer (2007).
Consists of two parts - "main article" (Large N Expansion. Vector Models) and a
"brief article" (BPHZL Renormalization).
