On the Cosine-Sine Operator Functional Equations (Short Communication) A.B. BUCHE — 1971 Aequationes mathematicae
On an exponential-cosine operator-valued functional equation. A.B. Buche — 1975 Aequationes mathematicae
On an Exponential-Cosine Operator-Valued Functional Equation. (Short Communication). A.B. Buche — 1975 Aequationes mathematicae
The generalized Cauchy equation for operator-valued functions. H.L. Vasudeva; A.B. Buche — 1976 Aequationes mathematicae
The generalized Cauchy equation for operator-valued functions. (Short Communication). H.L. Vasudeva; A.B. Buche — 1975 Aequationes mathematicae