Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
so sach » so sanh, bo sach, co sach
van anh » tuan anh, van minh
cac luu » cac luat, sach luu
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
lang ha » long ha
nang ma » tang ma, sang ma, nang cao
vi cua » vai cua, di cua
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: so sach y ((nang ma) or (lang ha)) hoi. hieu ve cac luu ((van anh) OR (van thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang ma) OR (lang ha)) hoi. hieu ve cac luu ((van anh) OR (van thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((nang ma) or (lang ha)) hoi. hieu ve cac luu ((van anh) OR (van thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang ma) or (lang ha)) hoi. hieu ve cac luu ((van anh) OR (van thanh)) vi cua tre*.