Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
hanh dung » thanh dung, anh dung, hanh dong
luan hang » luan han, luan hung, luan tang
luan nang » luan van, van nang, luan san
ho chieu » theo chieu, doi chieu, mot chieu
cong tap » cuong tap, cong tac, cong tan
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) or (hoc thieu)) sach - hanh dung ((luan hang) or (luan nang)) cong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) sach - hanh dung ((luan hang) OR (luan nang)) cong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (hoc thieu)) sach - hanh dung ((luan hang) or (luan nang)) cong tap toan cau*.