1. Hamilton, W.R.: ‘Elements of quaternions’, (Longmans, Green and Co. London 1866)
2. Artmann, B.: ‘The concept of number from quaternions to monads and topological fields’, Ellis Horwood series in mathematics and its applications(Ellis Horwood, Halsted Chichester 1988),Translation of: Der Zahlbegriff, Göttingen: Vandenhoeck & Rupprecht, 1983. Translated with additional exercises and material by H.B. Griffiths.
3. Quaternion-Fourier transforms for analysis of two-dimensional linear time-invariant partial differential systems
4. Blahut, R.E.: ‘Fast algorithms for digital signal processing’, (Addison-Wesley 1985)