| perf. |
трубы нефтяного сортамента (Pipe and tube products used in petroleum industry, such as drill pipe, pipe casings, oil pipes. ( , OCTG  businessdictionary.com)); трубы нефтяного сортамента (Pipe and tube products used in petroleum industry, such as drill pipe, pipe casings, oil pipes. ( – OCTG businessdictionary.com) Alexander Demidov) |
