1. Amyari, M., Chakoshi, M., Moslehian, M.S.: Quasi-representations of Finsler modules over $$C^*$$ C ∗ -algebras. J. Oper. Theory 70(1), 181–190 (2013)
2. Ando, T.: Linear Operators on Krein Spaces. Hokkaido University, Sapporo (1979)
3. Antoine, J.P., Ôta, S.: Unbounded GNS representations of $$C^*$$ C ∗ -algebra in a Krein space. Lett. Math. Phys. 18(4), 267–274 (1989)
4. Azizov, T.Y., Iokhvidov, I.S.: Linear Operators in Spaces with an Indefinite Metric. Nauka, Moscow (1986 English Translation). Wiley, New York (1989)
5. Bhat, B.V.R., Ramesh, G., Sumesh, K.: Stinespring’s theorem for maps on Hilbert $$C^*$$ C ∗ -modules. J. Oper. Theory 68(1), 173–178 (2012)