Each Schwartz Fréchet space is a subspace of a Schwartz Fréchet space with an unconditional basis Steven F. Bellenot (1980) Compositio Mathematica
Espacios de Fréchet de generación debilmente compacta. Manuel Valdivia (1987) Collectanea Mathematica
Every nuclear Fréchet space with a regular basis has the quasi-equivalence property Lawrence Crone, William Robinson (1975) Studia Mathematica
Existence of bases and the dual splitting relation for Fréchet spaces Jörg Krone (1989) Studia Mathematica