I came across the following theorem on Wikipedia's page on the tensor derivative.
$$\int_{\Omega}\boldsymbol{\nabla}\boldsymbol{G}\,d\Omega = \int_{\Gamma} \mathbf{n}\otimes\boldsymbol{G}\,d\Gamma \,.$$
It looks like the divergence theorem, but with a gradient instead of a divergence on the left, and an outer instead of an inner product on the right. The result unfortunately has no reference. The author refers to it simply as the divergence theorem.
I'm wondering if anyone could point me to a textbook, or even a field, where I could find this result. I have a number of books on tensor analysis but don't find anything like this form.
I had previously derived this result myself, not knowing that it was known to others. So if it is known in some community, I would like to be able to properly reference it.
I should add that I work in fluid mechanics and so am not very in touch with the most abstract representations of Stokes theorem.
Thanks!