Pictures of personality : guide to the four human natures / John Lopker

 Lopker, John;

Los Angeles : Typology , 2000

Tempe : kumpulan fakta menarik berdasarkan penelitian

 Winarno; Winarno, Wida; Winarno, A. Driando Ahnan;

Jakarta : Gramedia Pustaka Utama , 2017

State of the World 2009 into a warming world: a Worldwatch Institute report on progress toward a sustainable society

 Starke, Linda.; Worldwatch Institute.;

New York : W.W. Norton & Company , 2009