Perhaps you should try some spelling variations:
vat nhanh » vat thanh, phat nhanh, hat nhan
nhanh tai » nhanh thai, nhan tai, thanh tai
pham duy » pham duc
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
cuc tre » cua tre, cuu tre, cuc thue
duc tre » duoc tren, duc tien
su tai » tu tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su tai) or (su thi)) ky dang xa hoi. hieu ve pham duy vat nhanh tai ((cuc tre) OR (duc tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su tai) OR (su thi)) ky dang xa hoi. hieu ve pham duy vat nhanh tai ((cuc tre) OR (duc tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su tai) or (su thi)) ky dang xa hoi. hieu ve pham duy vat nhanh tai ((cuc tre) OR (duc tre))".
• Adding a wildcard symbol may retrieve word variants: ((su tai) or (su thi)) ky dang xa hoi. hieu ve pham duy vat nhanh tai ((cuc tre) OR (duc tre))*.