na INLIS000000001332659 ind 0010-0225000670 Peradaban Awal Gerry Bailey Gerry Bailey Dua PT. Ensiklopedia Nasional Indonesia, 2013 48 hlm. 29 cm. 978-979-798-508-0 R503 GER p 503 Ensiklopedia Sains 000000002685 000000002686 000000002687