Perhaps you should try some spelling variations:
khai thong » khai thuong, khap thong, khau thong
phan tong » phan trong, phan cong, han tong
hoat phan » hoa phan, thuat phan, hoc phan
sach tham » sach nha
sach dao » lanh dao
dao thuc » dan thuc, dao tuc, do thuc
thuc cac » thuc cach, tuc cac, phuc cac
cac hoat » cao hoat, cac khoan, cac thuat
tham hoa » pham hoa, thanh hoa, pham khoa
hoa sach » khoa sach, hoc sach, hoi sach
te sach » toc sach
sach ke » sach kem, sach de, sach che

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 dao thuc cac hoat phan tong ) or ( te sach tham hoa sach ke khai thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sach dao thuc cac hoat phan tong ) OR ( te sach tham hoa sach ke khai thong )).
• Adding a wildcard symbol may retrieve word variants: (( te sach dao thuc cac hoat phan tong ) or ( te sach tham hoa sach ke khai thong ))*.