1. ^Keith Weller Taylor The Birth of Vietnam 1991 Page 312 "By the middle of the second millennium B.C., Phung-nguyen had evolved into the Dong-dau culture, which Vietnamese archeologists regard as Middle Bronze Age. By the turn of the first millennium B.C., Dong-dau, in turn, evolved into the ..."
2. ^Terry E. Miller, Sean Williams The Garland handbook of Southeast Asian music 2008 Page 23 "Around 1500 B.C.E, the Phùng Nguyên culture was replaced by the Đồng Đậu culture, associated not only with a different type of pottery — vessels decorated with multiple parallel... Around 1100 B.C.E, the Đồng Đậu culture was succeeded by the Gò Mun culture, which lasted until about the fifth ..
3. ^Ian Shaw, Robert Jameson - A dictionary of archaeology - Page 205 2002 "Whereas the Phung Nguyen sites have very little evidence for copper-based technology, there is no doubt that metal casting became fully established in northern Vietnam during the Dong Dau culture, the sandstone and clay moulds as well as ..."
4. ^Charles Higham The Bronze Age of Southeast Asia 1996 Page 96 "Red River {{convert|35|km|0|abbr=on}} east of Phung Nguyen. It covers about 3 ha and has a cultural stratigraphy between 5 and 6 m deep. Its basal layer contains late Phung Nguyen pottery, but thereafter the assemblage developed into the Dong Dau culture."