Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
cong dung » cuong dung, cong dong, cong luong
dung data » dung dat, dung dan, dung danh
data phan » dam phan, sat phan, vat phan
dan cong » dang cong, van cong, dan dong
phan dau » phan tu, hang dau
hieu ca » hieu cac, hieu cua, hieu va
doc dan » duoc dan, hoc dan, doc dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((chieu sach) OR (hieu ca)) - than doc dan cong dung data phan dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((chieu sach) OR (hieu ca)) - than doc dan cong dung data phan dau*".