Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
van hanh » van thanh, ban hanh, van anh
thuc van » thuc vat, thuc dan, thuc va
cau thuc » cau truc, cuu thuc, can thuc
sach ly » sach y, sach lo, sach ty
hieu va » lieu va, hieu qua
hieu ve » hieu van
cao hoi » cau hoi, co hoi, cao hoc
ly nang » ky nang, ly hang, ly vang
va cuu » va cau, va huu
va chu » va che, va cau, va chi

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuat sach ly nang cao hoi. ((hieu ve) or (hieu va)) cau thuc van hanh ((va cuu) OR (va chu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ly nang cao hoi. ((hieu ve) OR (hieu va)) cau thuc van hanh ((va cuu) OR (va chu)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ly nang cao hoi. ((hieu ve) or (hieu va)) cau thuc van hanh ((va cuu) OR (va chu)) tre*".