Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh hai » thanh hai, nhanh hai, hang hai
thu sac » thu san, thu xac, thu dac
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
cac lo » cac lop, cac co, cac bo
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) or (thu sach)) ky nang xa hoi. hieu va cac lo va hanh hai ((cuu tre) OR (cua tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sac) OR (thu sach)) ky nang xa hoi. hieu va cac lo va hanh hai ((cuu tre) OR (cua tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu sac) or (thu sach)) ky nang xa hoi. hieu va cac lo va hanh hai ((cuu tre) OR (cua tre))".
• Adding a wildcard symbol may retrieve word variants: ((thu sac) or (thu sach)) ky nang xa hoi. hieu va cac lo va hanh hai ((cuu tre) OR (cua tre))*.