Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
trong van » trong cac
dong cong » duong cong, dung cong, dang cong
tang van » dang van, hoang van, tang luan
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
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: hoc thieu sach - hanh ((tang van) or (trong van)) dong cong dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - hanh ((tang van) OR (trong van)) dong cong dan toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - hanh ((tang van) or (trong van)) dong cong dan toan ban*.