Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
ban thanh » ban hanh, ban hang
nang cho » nang chon, ngang cho, nang cao
sach ty » sach tu, sach thu, xach tay
cac ban » cac dan, cac van, can ban
cuc tre » duc tre, cua tre, cuu tre
cho hoc » co hoc, khoa hoc
ve cac » va cac, vien cac
ve cam » ve cham, va cam, ve cai

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