AKIMOV, P. A.; NEGROZOV, O. A. ABOUT SOLUTION OF MULTIPOINT BOUNDARY PROBLEMS OF THREE-DIMENSIONAL STRUCTURAL ANALYSIS WITH THE USE OF COMBINED APPLICATION OF FINITE ELEMENT METHOD AND DISCRETE-CONTINUAL FINITE ELEMENT METHOD. PART 1: FORMULATION AND BASIC PRINCIPLES OF APPROXIMATION. International Journal for Computational Civil and Structural Engineering, v. 14, n. 2, p. 14–29, 29 Jun.2018.