Perhaps you should try some spelling variations:
sach tranh » canh tranh
cach nhanh » cac nganh, cac nhan, cac thanh
chong hiv » among hiv, chong vi
chong li » chong lai, cong li, hong li
te sach » toc sach
tranh o » tranh co, trang o, trinh o
te cach » ve cach, tu cach, te cac
o khi » co khi, bo khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te sach tranh o khi đong luc ) or ( te cach nhanh ((chong hiv) OR (chong li)) đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach tranh o khi đong luc ) OR ( te cach nhanh ((chong hiv) OR (chong li)) đong luc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sach tranh o khi đong luc ) or ( te cach nhanh ((chong hiv) OR (chong li)) đong luc ))".
• Adding a wildcard symbol may retrieve word variants: (( te sach tranh o khi đong luc ) or ( te cach nhanh ((chong hiv) OR (chong li)) đong luc ))*.