Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa
toc sach » hoc sach, doc sach, thuoc sach
nang tai » hang tai, tang tai, sang tai
hieu ve » hieu va, hieu van
tai hoi » tai khoi, dai hoi, tai hai
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du
y nang » ky nang, ly nang, v nang

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