@article {Bertola:Warped,
	title = {Warped products with special Riemannian curvature},
	journal = {Bol. Soc. Brasil. Mat. (N.S.)},
	volume = {32},
	number = {1},
	year = {2001},
	pages = {45{\textendash}62},
	issn = {0100-3569},
	author = {Marco Bertola and Gouthier, Daniele}
}
