1. Ando, T., Nishio, K.: Positive selfadjoint extensions of positive symmetric operators. Tohoku Math. J. 22, 65–75 (1970)
2. Arlinskiĭ, Y.M.: A class of contractions in a Hilbert space. Ukrain. Math. Zh. 39(6), 691–696 (1987). ((in Russian) English translation. in Ukr. Math. J. 39(6), 560–564 (1987))
3. Arlinskiĭ, Y.M.: Characteristic functions of operators of the class
$$C(\alpha )$$
C
(
α
)
. Izv. Vyssh. Uchebn. Zaved. Mat. 2, 13–21 (1991). ((in Russian).English translation in Sov. Math., 35(2), 13-23 (1991))
4. Bade, W.G.: An operational calculus for operators with spectrum in a strip. Pac. J. Math. 3, 257–290 (1953)
5. Batty, C.J.K.: Unbounded operators: functional calculus, generation, perturbations. Extr. Math. 24(2), 99–133 (2009)