Gaussian Integers
Futa, Yuichi, Okazaki, Hiroyuki, Mizushima, Daichi, Shidama, Yasunari
Open Mapping Theorem
Sakurai, Hideki, Kunimune, Hisayoshi, Shidama, Yasunari
Banach Algebra of Bounded Complex-Valued Functionals
Kanazashi, Katuhiko, Okazaki, Hiroyuki, Shidama, Yasunari