1. Structure of operators with numerical radius one;Ando, T.;Acta Sci. Math. (Szeged),1973
2. Subalgebras of 𝐶*-algebras. II;Arveson, William;Acta Math.,1972
3. A note on biquadratic forms;Calderón, A.-P.;Linear Algebra Appl.,1973
4. Completely positive linear maps on complex matrices;Choi, Man Duen;Linear Algebra Appl.,1975
5. Numerical ranges and dilations;Choi, Man-Duen;Linear and Multilinear Algebra,2000