1. Gurwell , W. E.Tungsten and Tungsten Alloys: Recent Advances, The Minerals, Metals & Materials Society, Warrendale , Pennsylvania , p p. 43 – 52 , ( 1991 ).
2. Gowri , S. , and J. A. Lund ,Metal Powder Industries Federation, Princeton , New Jersey , pp. 143 – 154 , ( 1993 ).