Perhaps you should try some spelling variations:
thanh hoi » thanh hoai, thanh hoa, thanh hai
nang mai » nang ma, nang tai, lang mai
mai khoi » mai khoa, tai khoa, cac khoi
thuc dan » thuc hanh, hoc dan, thuc vat
bo sach » co sach, hoc sach
thuc va » thuc vat, thuc day
hieu va » lieu va, hieu qua
hieu ve » hieu van
sach vu » sach va, sach tu, sach uu
vu nang » vuc nang, va nang, vu dang
hoi cua » hoi chuc

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach vu nang mai khoi. ((hieu ve) or (hieu va)) am ((thuc va) OR (thuc dan)) thanh hoi cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach vu nang mai khoi. ((hieu ve) OR (hieu va)) am ((thuc va) OR (thuc dan)) thanh hoi cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach vu nang mai khoi. ((hieu ve) or (hieu va)) am ((thuc va) OR (thuc dan)) thanh hoi cua vat".
• Adding a wildcard symbol may retrieve word variants: bo sach vu nang mai khoi. ((hieu ve) or (hieu va)) am ((thuc va) OR (thuc dan)) thanh hoi cua vat*.