$\oint{□}$ $\oint_{□}^{□}{□}$ $\oint\limits_{□}^{□}{□}$
$\int{□}$ $\int_{□}^{□}{□}$ $\int\limits_{□}^{□}{□}$
$\iint{□}$ $\iiint{□}$ $\iiiint{□}$
$\idotsint{□}$ $\int_{x=1}^{n}{x}\;dx$