Douglas & Raven, Genomes at the interface between bacteria and organelles, 2003, Philos.Trans.R.Soc.Lond B Biol.Sci., 358, 5-17

Doolittle,W.F., Boucher,Y., Nesbo,C.L., Douady,C.J., Andersson,J.O., Roger,A.J., How big is the iceberg of which organellar genes in nuclear genomes are but the tip?, 2003, 258, 39-57