Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cau theo » cau thi, cau tao
hieu van » hieu va, thien van, lieu va
nam thuc » nam thuoc, am thuc, nam thu
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
va danh » va dan, va hanh, dia danh
va dinh » van dinh, va kinh, va tinh
su sach » so sach, vu sach
di cau » da cau, diem cau

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

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