The term "satellite city" is used to describe the relationship between a large city and neighbouring smaller cities and towns that are economically dependent upon it.
Satellite cities may be collection and distribution points in the commercial linkages of a trading metropolis (大城市), or they may be manufacturing or mining centers existing with one-industry economies as the creatures of some nearby center. This latter form is what is generally meant when one uses the term "satellite city". Taken in this sense, nineteenth-century Chicopee and Lowell, Massachusetts, were satellites of Boston. Both were mill towns created by Boston investors to serve the economy of that New England metropolis. Located on cheap land along water-power sites in the midst of a farming region that could supply enough labor, they were satellites in the fullest sense of the term. Pullman, Illinois, and Gary, Indiana, were likewise one-industry towns created in conjunction with the much broader economy of nearby Chicago. Such places, as Vera Schlakman and Stanley Buder have pointed out in their excellent urban biographies, had a one-dimensional quality, a paucity (缺乏，少量) of social vigor. These cities could not stand alone; they were in a sense colonies of a multifunctional mother city. It can be inferred from the passage that Vera Schlakman and Stanley Buder are ______.