i feel compelled to warn, this places resources ANYWHERE in your Zone of control, this includes, stupidly, on the far, far fringes of a city at the border with a rival nation, so that in some circumstances, you are guarenteed to loose that resource when the rival increases his influence.
i have already been forced once to go to war to reclaim a spawned resource because while in my zone of control, it was so ridiculously on the fringes, that i was going to loose it, which ofcourse, once reclaimed, supplied the conquered city because it was closer. it should be limited in placement to ensure its yours, barring extreme events.