Perhaps you should try some spelling variations:
thieu hach » thien hach, chieu sach, hieu cach
phong gian » khong gian, phong giao, chong gian
gian dan » gian lang
dan dung » van dung, tin dung, ap dung
dung dat » dung va, dung tai
phan lap » phan dau
phan van » pham van, thanh van, luan van

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 - khanh phong gian dan dung dat ((phan lap) or (phan van))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc thieu hach - khanh phong gian dan dung dat ((phan lap) OR (phan van))*.