Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
nay thuc » nam thuc, cay thuc, day thuc
cau theo » cau thi, cau tao
hoc sach » hoc sinh, hoc cac, hoc anh
danh xa » danh ca, canh xa, dan xa
dinh xa » dinh ba, dinh va, dinh xu
hieu va » lieu va, hieu qua
thuc va » thuc vat, thuc dan, thuc day
dau vai » dau va, dau hai, dau tai
vai cau » va cau, van cau, vai cac
va nay » va ngay, va cay
va dau » va dao

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

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