s= ignored (|author= suggested) (help)CS1 maint: extra punctuation (link) CS1 maint: unrecognized language (link)↑ 2.0 2.1 "Los Alamos National Laboratory – Hafnium". සම්ප්‍රවේශය 2008-09-10.↑ Weeks, Mary Elvira (1932). "III. Some Eighteenth-Century Metals". Journal of Chemical Education: 1231–1243.↑ Urbain, M. G. (1922). "Sur les séries L du lutécium et de l'ytterbium et sur l'identification d'un celtium avec l'élément de nombre atomique 72 (The L series from lutetium to ytterbium and the identification of element 72 celtium". Comptes rendus (French බසින්). 174: 1347–1349. සම්ප්‍රවේශය 2008-10-30.{{cite journal}}:  CS1 maint: unrecognized language (link)↑ Coster, D. (1923-01-20). "On the Missing Element of Atomic Number 72". Nature. 111 (2777): 79–79. Bibcode:1923Natur.111...79C. doi:10.1038/111079a0. {{cite journal}}: Unknown parameter |coauthor= ignored (|author= suggested) (help)↑  {{cite book}}: Empty citation (help)↑ Barksdale, Jelks (1968). The Encyclopedia of the Chem