Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
hoc thieu » toc thieu, hoc hien
dung cong » dung trong
tung vat » dung vat, tang vat, luong vat
ban thai » ban than, ban thi, ban thoi
tung va » trung va, tuong va, dung va
ban tai » van tai, han tai, ban thi

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 - thanh ((tung vat) or (tung va)) dung cong ((ban thai) OR (ban tai)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sach - thanh ((tung vat) OR (tung va)) dung cong ((ban thai) OR (ban tai)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sach - thanh ((tung vat) or (tung va)) dung cong ((ban thai) OR (ban tai)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sach - thanh ((tung vat) or (tung va)) dung cong ((ban thai) OR (ban tai)) cao*.