In nearly all cases, a city represents the focal point of a large area which it dominates. As distance away from the city increases the influence of the city decreases until a point is reached where another city of similar size exerts more influence. The purpose of this study is to establish and discuss the major area of dominance for Omaha.
Retallick, Harold J.; Gildersleeve, Charles R.; and Lea, Donald W., "Omaha Trade Area Study No. 05: Omaha Spheres of Influence" (1968). Publications. 29.