Write an expression of Biot-Savart law in vector form.

The Biot-Savart law in vector form for a current element $I d\vec{l}$ at position vector $\vec{r}$ is: $d\vec{B} = \frac{\mu_{0}}{4\pi} \frac{I (d\vec{l} \times \vec{r})}{r^{3}}$ or $d\vec{B} = \frac{\mu_{0}}{4\pi} \frac{I (d\vec{l} \times \hat{r})}{r^{2}}$