APA
EDITH KAY PENDLETON et al, .HIDDEN WORLDS. WASHINGTON D.C., THE NATIONAL GEOGRAPHIC SOCIETY, 1985: .
Chicago
EDITH KAY PENDLETON et al, .HIDDEN WORLDS. WASHINGTON D.C., THE NATIONAL GEOGRAPHIC SOCIETY, 1985: .
Harvard
EDITH KAY PENDLETON et al, .HIDDEN WORLDS. WASHINGTON D.C., THE NATIONAL GEOGRAPHIC SOCIETY, 1985: .
MLA
EDITH KAY PENDLETON et al, .WASHINGTON D.C., THE NATIONAL GEOGRAPHIC SOCIETY, 1985: . .
