Perhaps you should try some spelling variations:
hoc nhanh » hoc nganh, hoc phan
toc sach » hoc sach, doc sach, thuoc sach
va hanh » van hanh, va thanh, va danh
cao tuc » dao tuc, cao duc, cao suc
hieu va » lieu va, hieu qua
tu tong » tu tuong, tu trong, tu dong
tu nong » tu dong, tu cong, tu tuong
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
tuc va » thuc va, truc va, tuc xa
vi cua » vai cua, di cua

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 nhanh)) ((tu nong) OR (tu tong)) xa hoi. hieu va cao tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc nhanh)) ((tu nong) OR (tu tong)) xa hoi. hieu va cao tuc va hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (hoc nhanh)) ((tu nong) OR (tu tong)) xa hoi. hieu va cao tuc va hanh vi cua tre*".