found: GEOnet, May 14, 2003 (Gran Chaco, PA, AR, BL, rgn, 23⁰00ʹ00ʺS 060⁰00ʹ00ʺW, variants: El Gran Chaco, El Chaco, Chaco)
found: Britannica Micro.:v. 4 (Gran Chaco, Chaco)
found: Web. geog.(Chaco, El Chaco, Gran Chaco)
found: Rand McNally(Gran Chaco)
found: Times atlas(Gran Chaco)
found: NGS atlas(Gran Chaco)
found: Touring club it. atlas(Gran Chaco, Chaco)
found: Lippincott(Chaco, Gran Chaco)
found: Acad. Am. encyc.:v. 4 (Chaco, Gran Chaco)
found: Collier's(Gran Chaco)
found: Americana(Chaco, Gran Chaco)
found: Medallion(Gran Chaco)
found: Old catalog heading(Chaco, El Gran)
found: GEOnet(plain; 23°00ʹ00ʺS 060°00ʹ00ʺW)
notfound: Hennepin