Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
phan cong » thanh cong
tinh son » tinh toan, dinh so, tinh hoc
son phan » so phan, bon phan, mon phan
dang van » hoang van, hang va
dung dat » dung va, dung tai
phan lap » phan dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc thieu sach - tinh son phan cong ((dang van) or (dung dat)) phan lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu sach - tinh son phan cong ((dang van) OR (dung dat)) phan lap.
• Adding a wildcard symbol may retrieve word variants: toc thieu sach - tinh son phan cong ((dang van) or (dung dat)) phan lap*.