Perhaps you should try some spelling variations:
thinh khong » tinh khong, trinh khong, thi khong
thieu hach » thien hach, chieu sach, hieu cach
gian dan » gian lang
dan dung » van dung, tin dung, ap dung
dung dat » dung va, dung tai
phan van » pham van, thanh van, luan van
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 hach - thinh khong gian dan dung dat ((phan van) or (phan lap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu hach - thinh khong gian dan dung dat ((phan van) OR (phan lap))*.