How can I cite software documentations?
In general, I would treat software documentation depending on how it's distributed.


If it's published in book form, then it should be cited as a book. The version number goes where you would put the edition, and the company that manufactures the software is the "publisher."
If the manual is distributed electronically, then you should cite the website from which it is obtained as the "source."
An exception to this is if you are asked in the documentation to reference a specific work (for instance, a research article, or a website) when citing a code. Then you should follow the specific guidance provided.