Perhaps you should try some spelling variations:
thanh di » thanh doi, thanh de, thanh dinh
thanh do » thanh de, thanh pho, thanh hoa
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
cuu tre » cua tre, cau tren, cau treo
y nang » ly nang, v nang, may nang
ve cac » va cac, vien cac

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