HEDEGĂ…RD, Per. Teori for supraledning. KVANT, [S. l.], v. 1, n. 3, 1990. DOI: 10.7146/kvant.169121. DisponĂ­vel em: https://tidsskrift.dk/KVANT/article/view/169121. Acesso em: 17 sep. 2026.