Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh dang » tranh hang, tran dang, tranh quang
cac nganh » hoc nganh
dang khai » dang khoi, dang hai, quang khai
nganh co » nganh cong, nganh hoa, nganh y
su sach » so sach, vu sach
su cac » tu cac, su cao, su can

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su cac nganh co khi đong luc ) or ( su sach tranh dang khai đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su cac nganh co khi đong luc ) OR ( su sach tranh dang khai đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( su cac nganh co khi đong luc ) or ( su sach tranh dang khai đong luc ))*.