fix typos

content/Math4201/Math4201_L39.md

@@ -25,7 +25,7 @@ $T=\mathbb{R}^2/\mathbb{Z}^2$ is a $2$-dimensional manifold.
 
 </details>
 
-Recall the [Urysohn metirzation theorem](./Math4201_L38.md/#urysohn-metirzation-theorem). Any normal and second countable space is metrizable.
+Recall the [Urysohn metirzation theorem](../Math4201_L38#urysohn-metirzation-theorem). Any normal and second countable space is metrizable.
 
 In the proof we saw that any such space can be embedded into $\mathbb{R}^\omega$ with the product topology.