Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
va thanh » gia thanh, ban thanh, va tinh
cau tren » cu tren, dau tren, ca tren
va hanh » van hanh, va danh, ban hanh
hieu ve » hieu va, hieu van
cac tac » cac toc, cac bac, cac dac
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
co hoi » co hoc
ve cau » ke cau, va cau, le cau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y nang ((co hoi) OR (co loi)). hieu ve cac tac ((va hanh) OR (va thanh)) ve cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y nang ((co hoi) or (co loi)). hieu ve cac tac ((va hanh) OR (va thanh)) ve cau tren~".
• Adding a wildcard symbol may retrieve word variants: thuat sach y nang ((co hoi) or (co loi)). hieu ve cac tac ((va hanh) OR (va thanh)) ve cau tren*.