This is a La Leche League article, with citations:
To those who can't wait until I wean Ari, I say there, now leave me alone!
She really is weaning herself, by the way. We are down to nursing four times a day and often she is nursing for a minute or so on each side. I am pretty certain that the before bed and morning feedings will be the last ones to go. Not sure which one will go first.