Perhaps you should try some spelling variations:
thanh dan » thanh san, thanh van, thanh dat
van thanh » ban thanh, van tuan
che toan » chi toan, che thanh, ke toan
loai hoc » logic hoc, loai khoa, dai hoc
hieu van » hieu va, thien van, lieu va
sach che » sach thue, sach nha, sach cap
su sach » so sach, vu sach
cua tre » cuu tre, cua triet, dua tren
van cau » van dau, van hau, van chat
luc van » luoc van, luu van, duc van
cau luc » cau truc, cau phuc
lai hoa » dai hoa
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach che toan ((lai hoa) OR (loai hoc)). hieu van cau luc van thanh dan ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach che toan ((lai hoa) OR (loai hoc)). hieu van cau luc van thanh dan ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach che toan ((lai hoa) OR (loai hoc)). hieu van cau luc van thanh dan ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: su sach che toan ((lai hoa) OR (loai hoc)). hieu van cau luc van thanh dan ((cua tre) or (cua te))*.