What is the difference, if any, between these symbols for surface integrals and line integrals?

Firstly, the AP Physics C equation sheet here (the page I am talking about is page 5) uses $\oint$ for Gauss's law, Ampere's law, and Faraday's Law. However, the Wikipedia page about Gauss's law uses a symbol I can't seem to get here (Wikipedia says its \oiint), but it's $\iint$ with a circle around it, like $\oint$. The page about Ampere's Law says that $\oint$ is a closed line integral, and that $\iint$ is a 2-D surface integral. Finally, the page on Faraday's Law uses just a single $\int$ for a surface integral, and $\oint$ for a line integral. My teacher uses the $\oint$ symbol for a surface integral.

However, on a Wikipedia page for the integral symbol, it says that \oiint is a closed surface integral, $\oint$ is a contour integral, and that $\iint$ is simply a double integral. However, on the Stoke's Theorem page, they use $\iint$ for a surface integral and $\oint$ for a line integral. The actual page on Wikipedia for line integrals simply uses $\int$, and the page for surface integrals uses $\iint$, which is what my calculus book (here) uses.

Which one is the most common way/the right way (if there is one)?

Using one or several integral symbols is also a matter of choice. As one grows in abstract thinking, an integral is an integral, and so $\iint$ is not really conveying more information that $\int$ if the rest of the context is clear. This is not different than going from $\int f(x)\,dx$ to $\int f$.
Finally, $\oint$ for an arbitrary surface integral makes no sense, as the canonical meaning of the circle is that the region of integration is closed (no boundary).