Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh cong » thanh cong, trinh cong, tran cong
sach nganh » sach ngan, cac nganh, sach danh
cong khi » cong thai, khong khi, co khi
su sach » so sach, vu sach
hoa phi » hoa phan, hoa thai
hoa hi » hoa hoi, hoa thi, hoa li

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: (( su sach tranh cong khi đong luc ) OR ( su sach nganh ((hoa hi) OR (hoa phi)) đong luc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( su sach tranh cong khi đong luc ) or ( su sach nganh ((hoa hi) OR (hoa phi)) đong luc ))~".
• Adding a wildcard symbol may retrieve word variants: (( su sach tranh cong khi đong luc ) or ( su sach nganh ((hoa hi) OR (hoa phi)) đong luc ))*.