Perhaps you should try some spelling variations:
pham duy » pham duc
tan hanh » tan thanh, tang hanh, toan hanh
hieu vu » hieu va, hieu ve, hieu su
cua tre » cuu tre, cua triet, dua tren
dai hoi » dai hoc, dai hai, dai moi
duy tan » duy tuan, duc tan, duy van
vu pham » su pham, vi pham, vu kham
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky nang ((ma hoi) or (dai hoi)). hieu vu pham duy tan hanh vi ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky nang ((ma hoi) OR (dai hoi)). hieu vu pham duy tan hanh vi ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky nang ((ma hoi) or (dai hoi)). hieu vu pham duy tan hanh vi ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sai ky nang ((ma hoi) or (dai hoi)). hieu vu pham duy tan hanh vi ((cua tre) OR (cua te))*.