During excavation 2004 in Du Sang rock-shelter ( Kim Boi, Hoa Binh)
10.500 years old chared fruit stone fragments of Canarium fruit as food remains excavated in the Hoabinhian cave of Con Mong (Thanh Hoa, Vietnam)
Studing on the dongsonian bronze drum excavated in burial field Dong Xa (Kim Dong, Hung Yen, Vietnam)
The Dongson man with war axe on his shultern as handle of a bronze dagger of 2300 years old.
Studing in a bronze casting workshop in Lang Rong (Van Lam, Hung Yen)