Is it possible to obtain Wikipedia backlinks?

Is it possible to obtain Wikipedia backlinks, because most of them are saying about dead links in Wikipedia
but I'm not sure about that.

It is possible to get link on Wikipedia in case that page where link is pointing is educative with relevant content and it is not selling or offering some services to third party.

Indeed all you have to do is signup as a contributor... However you need to contribute positively and it will be reviewed... Chances are if you are caught with self promo then I am sure you will be banned...

As Danny83 points out above its about educational/relevant content...

Also keep in mind Wikipedia links are NOFOLLOW... You may get some traffic.... and most search engines will not transfer any link juice wrt ranking on the SERPs - G for sure being one of them - the only exception I am aware of is duckduckgo (there may be others) whom have stated that they look at such authority sites and ignore NOFOLLOW in that specific case, that said duckduckgo has a very tiny market share and is nothing compared to the Giant G ;-) ...

Bottom line - I wouldn't bother trying to get a link on Wikipedia...