Fundamental central dispersions in a double system 〈 〈 𝔊 〉 〉 Erich Barvínek (1971) Archivum Mathematicum
Fundamental decay mode and asymptotic behaviour of positive semigroups Ivo Marek (1980) Czechoslovak Mathematical Journal
Fundamental operator-valued functions of singular differential operators in Banach spaces. Falaleev, M.V. (2000) Sibirskij Matematicheskij Zhurnal