RADECKI, Karol. Perspective for Using the Optical Frequency Standards in Realization of the Second. Journal of Telecommunications and Information Technology, Warsaw, Poland, v. 37, n. 3, p. 111–115, 2009. DOI: 10.26636/jtit.2009.3.947. Disponível em: https://jtit.pl/jtit/article/view/947. Acesso em: 16 jul. 2026.