Multiple values on single keyword query (URI)

Hi.

I've been trying to find out how I can search for multiple values on the same parameter. Must be a URI request!

Ex:

_search?q=%2Buser:adam%20OR%20user:eve
_search?q=%2Buser:adam%20%2Buser:eve
_search?q=%2Buser:adam,eve

The problem is that only one of the parameters is prioritized (or show nothing at all), and I can't search for multiple values. Anyone know how to search one keyword with multiple values?

Seems like it works with the 3rd url.

=> _search?q=%2Buser:adam,eve