Continued Fractions of Period Six and Explicit Representations of Fundamental Units of Some Real Quadratic Fields

In the literature, it is very important to investigate the fundamental unit for studying the class number for the real quadratic fields; Furthermore, explicit form of the fundamental unit of real quadratic fields K = Q(√d) such that disa positive square free integer is not well-known except for the real quadratic fields of Richaut-Degert type.