Vassilev, Gueorgui P, Gueorgui Penev Vassilev, Nikolina Milcheva, Marie-Christine Record, and Rositsa Mancheva. 2012. “Diffusion Couple Studies of the Ni–Bi–Sn System”. Journal of Mining and Metallurgy, Section B: Metallurgy 48 (3): 347. https://asistent.ceon.rs/index.php/jmm/article/view/2453.