Perhaps you should try some spelling variations:
can thuc » dan thuc, van thuc, cay thuc
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
sach tu » sach thu, cach tu, sach ty
te sach » toc sach
hieu va » lieu va
tu nang » tru nang, tu nong, tu nano
va cuu » va cau, va huu
va chu » va che, va cau, va chi
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach tu nang x hoi. ((hieu va) or (hieu qua)) can thuc dan hanh ((va cuu) OR (va chu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach tu nang x hoi. ((hieu va) OR (hieu qua)) can thuc dan hanh ((va cuu) OR (va chu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach tu nang x hoi. ((hieu va) or (hieu qua)) can thuc dan hanh ((va cuu) OR (va chu)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach tu nang x hoi. ((hieu va) or (hieu qua)) can thuc dan hanh ((va cuu) OR (va chu)) tre*.