Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
dai thuc » dan thuc, dai thu, dai thua
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
hieu va » lieu va, hieu qua
vu nang » vuc nang, va nang, vu dang
va dai » va dao, vi dai, va dau
v nang » va nang, van nang, voi nang
vi cua » vai cua, di cua
cua te » cua tu

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)) ((v nang) or (vu nang)) xa hoi. hieu va dai thuc va hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ((v nang) OR (vu nang)) xa hoi. hieu va dai thuc va hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ((v nang) or (vu nang)) xa hoi. hieu va dai thuc va hanh vi cua te*.