Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh do
hanh doi » hanh noi, hang doi, hanh moi
te sach » toc sach
cac luc » cau luc, coc luc, cac nuoc
luc van » luoc van, luu van, duc van
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
cho hoc » khoa hoc
cua cau » cua cac, cua chu, cua cay
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: te sach ty xang ((cho hoc) or (co hoc)). hieu ve cac luc van ((hanh doi) OR (thanh doi)) cua cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty xang ((cho hoc) OR (co hoc)). hieu ve cac luc van ((hanh doi) OR (thanh doi)) cua cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty xang ((cho hoc) or (co hoc)). hieu ve cac luc van ((hanh doi) OR (thanh doi)) cua cau*".