The first part of the report is devoted to multi-loop calculations in the φ4+φ6 model. At the beginning the model will be discussed and compared with the φ4 model. A computer programme have been developed using GraphState and Graphine libraries to do multi-loop calculations. An implementation of the programme and its internal structure will be considered. The used calculation methods and libraries the programme is based on will be briefly discussed. With the help of the programme researchers have conducted six-loop calculations. The obtained results will be presented and compared with previously known ones. In the second part of the report there will be a discussion on the star-triangle transformation and an attempt to use some considerations to get a more general relation than the uniqueness relation.