[1] |
S. K. Berberian, Extensions of a theorem of Fuglede and Putnam, Proc. Amer. Math. Soc. 71 (1978), no. 1, 113 – 114. · Zbl 0388.47019 |
[2] |
Takayuki Furuta, Kyoko Matsumoto, and Nobuhiro Moriya, A simple condition on hyponormal operators implying subnormality, Math. Japon. 21 (1976), no. 4, 399 – 400. · Zbl 0356.47016 |
[3] |
Paul R. Halmos, A Hilbert space problem book, D. Van Nostrand Co., Inc., Princeton, N.J.-Toronto, Ont.-London, 1967. · Zbl 0144.38704 |
[4] |
C. R. Putnam, On normal operators in Hilbert space, Amer. J. Math. 73 (1951), 357 – 362. · Zbl 0042.34501 · doi:10.2307/2372180 |
[5] |
Joseph G. Stampfli and Bhushan L. Wadhwa, An asymmetric Putnam-Fuglede theorem for dominant operators, Indiana Univ. Math. J. 25 (1976), no. 4, 359 – 365. · Zbl 0326.47028 · doi:10.1512/iumj.1976.25.25031 |