[en] The programme SCORE-3 is described. It gives the solution for the one-velocity kinetic equation in a multiregion infinite cylinder in the P₃-approximation, taking into account third moments in the scattering indicatrix and the first six moments in the source, with boundary conditions appropriate as well for the cell as for the reactor. The solution is found with a network method and the method of matrix factorisation. The programme is written in ALGOL-60. The solution time is less than 18 s and is proportional to the number of network points. The preparation of input data is described and the input data itself is presented. The programme can be run on any computer with an ALGOL-compiler