Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thuc day » thuc dan, thuc vat
nam thuc » nam thuoc, am thuc, nam thu
cau theo » cau thi, cau tao
lang ha » long ha
sach ky » sac ky, sach y, sach ty
lang xa » dang xay, lang van
day dan » day danh, dao dan, cay dan
dan vai » dan va, dan tai, dan vat
vai cau » va cau, van cau, vai cac
hieu va » hieu qua

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky ((lang xa) or (lang ha)) hoi. ((hieu va) or (lieu va)) nam thuc day dan vai cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky ((lang xa) OR (lang ha)) hoi. ((hieu va) OR (lieu va)) nam thuc day dan vai cau theo.
• Adding a wildcard symbol may retrieve word variants: hoc sach ky ((lang xa) or (lang ha)) hoi. ((hieu va) or (lieu va)) nam thuc day dan vai cau theo*.