Statistik - Sutrisno Hadi (Andi Offset, 1975)
Oen, Jil. 2=c.1/ir, Jil.1=c.1-3/oen, jil.2=c.2-4/tr, jil.3=c.1-3/ir, jil.1,c.4 ; jil.2,c.5/ir,jil.1,c.5/tr, jil.1=c.6