Perhaps you should try some spelling variations:
duong manh » duong van
chieu sach » chinh sach, chiet tach, chieu sang
hanh hinh » hanh chinh, hanh tinh, hanh dinh
mot duong » mat duong, mon duong, mot dong
ho chieu » theo chieu, hoc thieu, doi chieu
hinh cua » chinh cua, sinh cua, tinh cua
toan cao » toan tap
toan ban » van ban

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 sach - hanh hinh cua mot duong manh ((toan cao) or (toan ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sach - hanh hinh cua mot duong manh ((toan cao) OR (toan ban)).
• Adding a wildcard symbol may retrieve word variants: ho chieu sach - hanh hinh cua mot duong manh ((toan cao) or (toan ban))*.