Fuente TeX:

\phi(r)=\frac{1}{4\pi\epsilon_0}\bigg(\oint_{S_0}\frac{\vec{P}\cdot\vec{n}da^\prime}{|\vec{r}-\vec{r}^\prime|}+\int_{V_0}\frac{-\nabla^\prime \vec{P}dv^\prime}{|\vec{r}-\vec{r}^\prime|}\bigg)