Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
lang van » dang van, tang van, hoang van
van hoi » van hoa, van hoc, van hoe
sach ky » sach y, sach ty, sach kem
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((sach ky) OR (sac ky)) lang van hoi. lieu va cam ((duc va) or (tuc xa)) thanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((sach ky) OR (sac ky)) lang van hoi. lieu va cam ((duc va) OR (tuc xa)) thanh tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((sach ky) OR (sac ky)) lang van hoi. lieu va cam ((duc va) or (tuc xa)) thanh tai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc ((sach ky) OR (sac ky)) lang van hoi. lieu va cam ((duc va) or (tuc xa)) thanh tai cua tre*.