Perhaps you should try some spelling variations:
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
trinh phan » trinh han, thanh phan, trinh toan
trinh quan » tinh quang, trinh luat, trinh han
chung nong » chung thong, chuong dong, hang nong
nong manh » nong lanh, duong manh, hoang manh
manh toan » thanh toan, anh tuan, tinh 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: hoc ((thieu sach) or (chieu sach)) - hanh ((trinh phan) OR (trinh quan)) chung nong manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (chieu sach)) - hanh ((trinh phan) OR (trinh quan)) chung nong manh toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (chieu sach)) - hanh ((trinh phan) OR (trinh quan)) chung nong manh toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (chieu sach)) - hanh ((trinh phan) OR (trinh quan)) chung nong manh toan cau*.