Perhaps you should try some spelling variations:
sach tranh » canh tranh
tranh cong » thanh cong, trinh cong, tran cong
cong khi » cong thai, khong khi, co khi
tu sach » thu sach, su sach, tu cach
nha hoc » nha thuoc, khoa hoc, nha nuoc
hoc khi » hoc khoi, hoc khia, hoc ki
te sach » toc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu sach nha hoc khi đong luc ) or ( te sach tranh cong khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach nha hoc khi đong luc ) OR ( te sach tranh cong khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( tu sach nha hoc khi đong luc ) or ( te sach tranh cong khi đong luc ))*.