00537naa#a2200181#i#450# EN\\bibl\14319 20240723001645.2 1999-8775 20140930b2014####ek#y0engy0150####ca RUS RU Periodic solutions of a quasilinear wave equations with variable coefficients. Journal article Bryansk Bryansk State Technical University 2014 8 с. Journal article local Rudakov Igor Lukavyy Aleksey bstu.editorum.ru