A convention sometimes used in physics journals is to "collapse" a group of related citations into a single entry in the bibliography. BibTeX, by default, can't cope with this arrangement, but the mcite package deals with the problem.
The package overloads the \cite command, so that citations of the
form \cite{paper1,paper2} appear in the document as a
single citation, and appear arranged appropriately in the bibliography
itself. You need to alter the bibliography style (.bst) file you
use; the pakage documentation tells you how to do that.