Don't get it out Oscar I will believe you and there is no need for dueling references on this one.There is a common mis-apprehension around here that trees are self fertile.Even the trees are fooled.
You may have enough trees in your area planted close enough to keep them all pollen happy. In a place like Mexico where trees is very rare it's going to be a very different story.
I researched this topic quite a bit because of a solitary tree i have that never fruits, but flowers like crazy. Most books say they are self pollinating or don't mention anything about pollination mechanism of this species. Only Prosea book it seems got this one correctly.