I am looking for reference for following lemma.
Consider a set of hyperplanes $H$ in a $n$-dimensional space. Let $S$ be the set of intersections of all elements of $H$.
Take a point $w$. Repeat as follows: project $w$ on a hyperplane in $H$. If you repeat this, you will get closer to $S$. If you use all hyperplanes infinitely often, you converge to $S$.
In what books I can find such sort of results?