Perhaps you should try some spelling variations:
vat thanh » dat thanh, gat thanh, tat thanh
toc sach » hoc sach, doc sach, thuoc sach
thanh ca » thanh cha, thanh cac, thanh ha
tang van » dang van, hoang van, trong van
cac thuc » cach thuc, cac thu, can thuc
tu sach » thu sach, su sach, te sach
cua tre » cuu tre, cua triet, dua tren
hieu ve » hieu va, hieu van
van hoi » van hoa, van hoc, van hoe
ky tang » ky nang, ky dang, kho tang
ve cac » va cac, vien cac
cua te » cua tu

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) or (toc sach)) ky tang van hoi. hieu ve cac thuc vat thanh ca ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky tang van hoi. hieu ve cac thuc vat thanh ca ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky tang van hoi. hieu ve cac thuc vat thanh ca ((cua tre) or (cua te))*.