In this paper, we present a new algorithm for the "n₁ × n₂ ×. . . × nₖ points problem" (an extension of the well-known "nine dots puzzle" of Samuel Loyd), able to solve completely the problem for the case "k=2" and, at the same time, provide lower upper bounds for the subsequent cases.
Valerio Bencini (2017) studied this question.