Perhaps you should try some spelling variations:
trinh vat » trinh van, trinh luat, sinh vat
toc sach » hoc sach, doc sach, thuoc sach
tang van » dang van, hoang van, trong van
tu sach » thu sach, su sach, te sach
tinh va » tich va, trinh van, tinh gia
hieu ve » hieu va, hieu van
van hoi » van hoa, van hoc, van hoe
ky tang » ky nang, ky dang, kho tang
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
cac tu » cac thu, cach tu, cac du

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 tu va ((tinh va) or (trinh vat)) cua tre~.
• 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 tu va ((tinh va) OR (trinh vat)) cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky tang van hoi. hieu ve cac tu va ((tinh va) or (trinh vat)) cua tre*.