[
[1] J.K. Chung, Pl. Kannappan, and C.T. Ng, A generalization of the cosine-sine functional equation on groups, Linear Algebra Appl. 66 (1985), 259–277.10.1016/0024-3795(85)90137-5
]Search in Google Scholar
[
[2] B. Ebanks, Some trigonometric functional equations on monoids generated by their squares, Aequationes Math. 95 (2021), 383–391.10.1007/s00010-020-00730-5
]Search in Google Scholar
[
[3] B. Ebanks, The cosine and sine addition and subtraction formulas on semigroups, Acta Math. Hungar. (2021). DOI: 10.1007/s10474-021-01167-110.1007/s10474-021-01167-1
]Search in Google Scholar
[
[4] B. Ebanks, C.T. Ng, Levi-Civita functional equations and the status of spectral synthesis on semigroups, Semigroup Forum 103 (2021), 469–494.10.1007/s00233-021-10211-z
]Search in Google Scholar
[
[5] H. Stetkær, Functional Equations on Groups, World Scientific, Singapore, 2013.10.1142/8830
]Search in Google Scholar
[
[6] H. Stetkær, A Levi-Civita functional equation on semigroups, (manuscript received July 30, 2020).
]Search in Google Scholar
[
[7] L. Székelyhidi, Convolution Type Functional Equations on Topological Abelian Groups, World Scientific, Singapore, 1991.10.1142/1406
]Search in Google Scholar
