1. Adler, S.L.: Quaternionic Quantum Mechanics and Quantum Fields, p. 586. Oxford University Press, New York (1995)
2. Agrawal, S., Kulkarni, S.H.: Dual spaces of quaternion normed linear spaces and reflexivity. J. Anal. 8, 79–90 (2000)
3. Agrawal, S., Kulkarni, S.H.: An analogue of the Riesz–representation theorem. Novi Sad J. Math. 30(1), 143–154 (2000)
4. Alpay, D., Shapiro, M.: Reproducing kernel quaternionic pontryagin spaces. Integr. Equ. Oper. Theory 50, 431–476 (2004)
5. Alpay, D., Luna-Elizarrarás, M.E., Shapiro, M.: Normes des extensions quaternionique d’operateurs réels. C. R. Acad. Sci. Ser. I Math. 340, 639–643 (2005)