Perhaps you should try some spelling variations:
thanh do » thanh pho, thanh hoa, thanh loi
toc sach » hoc sach, doc sach, thuoc sach
nang dau » hang dau, xang dau, nang du
thanh de » hanh de, thanh ve, thanh le
cac dac » cac dan, cac dai, cac bac
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
dau hoi » cau hoi, dai hoi, dan hoi
dac va » duc va, day va, dat va
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: ((te sach) OR (toc sach)) ky nang dau hoi. hieu ve cac dac va ((thanh de) or (thanh do)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang dau hoi. hieu ve cac dac va ((thanh de) OR (thanh do)) cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang dau hoi. hieu ve cac dac va ((thanh de) or (thanh do)) cuu tre*".