Perhaps you should try some spelling variations:
thu hang » thuc hanh, thu huong, thu trang
thuc van » thuc dan, thuc va, thuc hanh
thi hang » thi hanh, thi nang, thi hong
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
co loi » co hoi
va cau » van cau, va cac, va dau
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: tu sach ((thu hang) OR (thi hang)) co loi. hieu va cau ((thuc van) or (thuc vat)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((thu hang) OR (thi hang)) co loi. hieu va cau ((thuc van) OR (thuc vat)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((thu hang) OR (thi hang)) co loi. hieu va cau ((thuc van) or (thuc vat)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((thu hang) OR (thi hang)) co loi. hieu va cau ((thuc van) or (thuc vat)) hanh vi cua tre*.