Makanin, G. S. Equations in a free group. (Russian) Zbl 0511.20019 Izv. Akad. Nauk SSSR, Ser. Mat. 46, No. 6, 1199-1273 (1982). MSC: 20E05 20F05 PDFBibTeX XMLCite \textit{G. S. Makanin}, Izv. Akad. Nauk SSSR, Ser. Mat. 46, 1199--1273 (1982; Zbl 0511.20019)
Makanin, G. S. Recognition of the rank of equations in a free semigroup. (Russian) Zbl 0409.20044 Izv. Akad. Nauk SSSR, Ser. Mat. 43, 547-602 (1979). MSC: 20M05 20-04 PDFBibTeX XMLCite \textit{G. S. Makanin}, Izv. Akad. Nauk SSSR, Ser. Mat. 43, 547--602 (1979; Zbl 0409.20044)