Perhaps you should try some spelling variations:
tren truoc » trang truoc, tren thuc
tranh thuc » trinh thuc, trang thuc, thanh thuy
khoa khoi » khoa hoi, khoa khoa, thoat khoi
sach tren » sach tien, sach tranh
truoc cac » truoc cach, truoc cang, truoc cuoc
thuc cac » thuc cach, tuc cac, phuc cac
cac khoa » cac khoan, cac khoi, dac khoa
tu canh » thu canh, tu chanh, tu can
te sach » toc sach
khoa he » hoa he, khoa hoc, khong he
khong » phong
thong » trong

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu canh tranh thuc cac khoa khoi khong ) or ( te sach tren truoc cac khoa he thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu canh tranh thuc cac khoa khoi khong ) OR ( te sach tren truoc cac khoa he thong )).
• Adding a wildcard symbol may retrieve word variants: (( tu canh tranh thuc cac khoa khoi khong ) or ( te sach tren truoc cac khoa he thong ))*.