“…In the last decade, the communities of Calculus of Variations and Geometric Measure Theory made some efforts to study (Gilbert-)Steiner problems in many aspects, such as existence, regularity, stability and numerical feasibility (see for example [30,28,23,24,15,16,27,10,26,6,8,7] and references therein). Among all the significant results, we would like to mention recent works in [23,24] and [6,7], which are closely related to the present paper.…”