  The Multiple Travelling Salesman Problem (MTSP) is among the most interesting
combinatorial optimization problems because it is widely adopted in real-life
applications, including robotics, transportation, networking, etc. Although the
importance of this optimization problem, there is no survey dedicated to
reviewing recent MTSP contributions. In this paper, we aim to fill this gap by
providing a comprehensive review of existing studies on MTSP. In this survey,
we focus on MTSP's recent contributions to both classical vehicles/robots and
unmanned aerial vehicles. We highlight the approaches applied to solve the MTSP
as well as its application domains. We analyze the MTSP variants and propose a
taxonomy and a classification of recent studies.
