Continued Fractions of Quadratic Numbers

In this paper, we will first summarize known results concerning continued fractions. Then we will limit our consideration to continued fractions of quadratic numbers. The second author described periods and sometimes precise form of continued fractions of $\sqrt{N}$, where $N$ is a natural number. In cases where we were able to find such results in literature, we recall the original authors, however many results seem to be new.