Perhaps you should try some spelling variations:
pham duy » pham duc
ky lang » ky nang, ky dang, ky tang
hieu va » lieu va, hieu qua
va pham » van pham, va phat, va phap
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
su cac » tu cac, su cao, su can
ha hoi » hoa hoi, ha noi, va hoi
duy va » duy vat, duy van, day va
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su cac ky lang ((ha hoi) or (xa hoi)). hieu va pham duy va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su cac ky lang ((ha hoi) OR (xa hoi)). hieu va pham duy va hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su cac ky lang ((ha hoi) or (xa hoi)). hieu va pham duy va hanh vi cua tre*.