Perhaps you should try some spelling variations:
thanh hoa » thanh pho
thanh hai » thanh phan, thanh san
mai khoi » mai khoa, tai khoa, dai khoa
cac khoi » cac thoi, cac khoan, cach thoi
te sach » toc sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
cua tre » cua te, cuu tre, cua triet

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 ly nang ((mai khoi) OR (cac khoi)). hieu va cac duc va ((thanh hai) or (thanh hoa)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly nang ((mai khoi) OR (cac khoi)). hieu va cac duc va ((thanh hai) OR (thanh hoa)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly nang ((mai khoi) OR (cac khoi)). hieu va cac duc va ((thanh hai) or (thanh hoa)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ly nang ((mai khoi) OR (cac khoi)). hieu va cac duc va ((thanh hai) or (thanh hoa)) cua tre*.