In T33597, a responsive reference list based on the column-width CSS setting was introduced to MediaWiki. However, it appears that the same formatting is not available for mobile devices, which may still have some interest by using the screen in either a horizontal or a vertical fashion. Please add a similar CSS declaration to the mobile sites.
As @Arthur2e5 points out the current Minerva skin is purposely restricted to 55.8em
This means references will never be split into 2 columns as 30em*2=60em.
Dropping it to 25em would mean the css applies here and no more than 2 columns would ever be used to display references. I'm not sure if @Nirzar or another designer has any views there.
We can do this either as a skinStyle or for all skins.