Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cau duc » cao duc, cau luc, chu duc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, me hoi
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: tu sach y nang ((ma hoi) OR (ma hoa)). ((hieu ve) or (lieu va)) cau duc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((ma hoi) OR (ma hoa)). ((hieu ve) OR (lieu va)) cau duc va hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((ma hoi) OR (ma hoa)). ((hieu ve) or (lieu va)) cau duc va hanh vi cua tre*".