Perhaps you should try some spelling variations:
sach nganh » sach ngan, cac nganh, sach danh
nganh cong » nhanh chong, thanh cong
sach tranh » canh tranh
cong khi » cong thai, khong khi, co khi
dang hai » dang khai, dung hai, dong hai
hang hai » hoang hai, hang tai, thanh hai
vu sach » vu bach, vu khach
su sach » so sach

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach nganh cong khi đong luc ) OR ( su sach tranh ((dang hai) OR (hang hai)) đong luc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vu sach nganh cong khi đong luc ) or ( su sach tranh ((dang hai) OR (hang hai)) đong luc ))~".
• Adding a wildcard symbol may retrieve word variants: (( vu sach nganh cong khi đong luc ) or ( su sach tranh ((dang hai) OR (hang hai)) đong luc ))*.