Perhaps you should try some spelling variations:
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
trang ngan » trong nganh, trong ngang, toan ngan
dang cuong » dang cong, tang cuong, quang cuong
cuong manh » duong manh, cuong danh, luong manh
trang nap » trang va, trang ha, trang tai
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 ((trang nap) OR (trang ngan)) dang cuong manh toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (chieu sach)) - hanh ((trang nap) OR (trang ngan)) dang cuong manh toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (chieu sach)) - hanh ((trang nap) OR (trang ngan)) dang cuong manh toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (chieu sach)) - hanh ((trang nap) OR (trang ngan)) dang cuong manh toan cau*.