Perhaps you should try some spelling variations:
thach gian » thach giang, thanh gian, thanh giang
hang dang » hoang dang, hang hang, dang dang
doc hieu » hoc thieu, hoc hien
gian dat » gian dan, gian dac, giang day
dat hang » dat khanh, dat quang, tat thang
dang van » hoang van, hang va
van tho » van thao, van thu, van thi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (toc thieu)) sach - thach gian dat hang dang van tho ca~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) sach - thach gian dat hang dang van tho ca*.