[scantis]

No it is not. It is not a primary source, it is a collection of some sources, the information is freely edited by anyone. People who put a lot of effort into piling up the knowledge of humanity into the Wikipedia are just human.

Even though it is one of the most valuable collections of human knowledge and a giant effort, with absolute astonishing quality, that is also free and easy accessable to everyone, it isn't safe.

You can never trust it, you can not cite it and you should know it is full of mistakes. Better check the sources for yourself, it is sometimes worthy to take a look at the discussion.

If you stumble upon a mistake, you are accosted to improve upon it, using the edit function.