Perhaps you should try some spelling variations:
hanh hai » thanh hai, nhanh hai, hang hai
thu sac » thu sach, thu san, thu xac
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
va hanh » van hanh, va thanh, va danh
cua tre » cuu tre, cua triet, dua tren
sac ky » cac ky, sai ky
cac lo » cac lop, cac co, cac bo
cua te » cua tu
lo va » lo van, lao va, ly va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sac ky nang xa hoi. ((hieu va) or (hieu qua)) cac lo va hanh hai ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang xa hoi. ((hieu va) OR (hieu qua)) cac lo va hanh hai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang xa hoi. ((hieu va) or (hieu qua)) cac lo va hanh hai ((cua tre) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: thu sac ky nang xa hoi. ((hieu va) or (hieu qua)) cac lo va hanh hai ((cua tre) OR (cua te))*.