Perhaps you should try some spelling variations:
nhung duong » nhung dung, nhung huong, nhung tuong
duong manh » duong van
tieu sach » chieu sach, dien sach, te sach
manh toan » thanh toan, anh tuan, tinh toan
dung thi » dung tai, dung chi, dung thu
dung tri » dung tai, dung tren, dung sai
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: theo tieu sach - nhanh ((dung thi) OR (dung tri)) nhung duong manh toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu sach - nhanh ((dung thi) OR (dung tri)) nhung duong manh toan cau".
• Adding a wildcard symbol may retrieve word variants: theo tieu sach - nhanh ((dung thi) OR (dung tri)) nhung duong manh toan cau*.