1. Horadam A.F.: Complex Fibonacci Numbers and Fibonacci Quaternions. Amer. Math. Monthly 70, 289–291 (1963)
2. Horadam A.F.: Quaternion Recurrence Relations. Ulam Quaterly 2, 23–33 (1993)
3. Iakin A.L.: Generalized Quaternions of Higher Order. The Fib. Quart. 15, 343–346 (1977)
4. Iakin A.L.: Generalized Quaternions with Quaternion Components. The Fib. Quart. 15, 350–352 (1977)
5. Ward J.P.: Quaternions and Cayley Numbers. Kluwer, London (1996)