For citations:

Romantzev B.A., Lube I.I. BLANK TWO-ROLL PIERCING PROCESS INTO HOLLOW BILLET WITH DIAMETER STROKE ON MISIS SCREW-ROLLING MILL STUDY. Izvestiya. Ferrous Metallurgy. 2012;55(1):41-45. (In Russ.) https://doi.org/10.17073/0368-0797-2012-1-41-45