Talk:Oberon (Warframe)/@comment-213.161.29.60-20140609162620/@comment-50.103.1.91-20140609200424

They drop pretty evenly for all Eximus units. If you're farming Oberon (for some reason), you probably want to run high-volume lowish level missions.

I recommend Survival and Defense Missions on Earth personally; but any location where you can get incidental drops for rare resources is a good choice.