@article {66123,
	title = {Using particle swarm optimization with function stretching (SPSO) for inverting gravity data: A visibility study},
	journal = {Journal of Physics and mathematics, Science Bull},
	volume = {V 86 },
	year = {2008},
	pages = {259-283 },
	author = {N.H. Sweilam and Gobashy,M. M and Hashem , T}
}
