\documentclass[12pt]{article}
\usepackage{amsmath,amssymb,amsfonts}
\begin{document}
In this paper, we consider a multi-sourceWeber problem of m new facilities
with respect to n demand regions in order to minimize the sum of the transportation
costs between these facilities and the demand regions. We find a point on the border
of each demand region from which the facilities serve the demand regions at these
points. We present an algorithm including a location phase and an allocation phase
in each iteration for solving this problem. An algorithm is also proposed for carrying
out the location phase. Moreover, global convergence of the new algorithm is proved
under mild assumptions, and some numerical results are presented.
\end{document}