Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
tu sach » thu sach, su sach, te sach
dang xa » dang xay, lang xa, dang ha
hieu va » hieu qua
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
cam lo » nam lo, cam ly, cam o
va dat » va dao, va dau, va dap
va cua » va chua, via cua, ca cua
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: ((tu sach) or (hoc sach)) ky dang xa hoi. ((hieu va) or (lieu va)) cam lo va dat va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (hoc sach)) ky dang xa hoi. ((hieu va) OR (lieu va)) cam lo va dat va cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (hoc sach)) ky dang xa hoi. ((hieu va) or (lieu va)) cam lo va dat va cua tre*.