@article {6,
	title = {Evaluating alternative hypotheses for the early evolution and diversification of ants},
	journal = {PNAS},
	volume = {103},
	year = {2006},
	month = {28/11/2006},
	pages = {18172{\textendash}18177},
	author = {Sean G. Brady and Ted R. Schultz and Brian L. Fisher and Philip S. Ward}
}
