Perhaps you should try some spelling variations:
khan thong » khap thong, khau thong, nhan thong
phap phong » hai phong, phap phan
khoa phap » khoa phau, khoan phai, khong phap
thai thuc » thai thuy, thai tuc, tham thuc
tu doanh » su doanh, te doanh, ty doanh
tai thuc » tri thuc, dai thuc, thi thuc
thuc cac » thuc cach, tuc cac, phuc cac
cac khoa » cac khoan, cac khoi, dac khoa
hanh kho » hanh khu, hang khoa, hanh theo
kho khan » khoa kham, khoa than
tu toc » tu hoc, tu goc, tu tot

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: (( tu doanh tai thuc cac khoa phap phong ) OR ( tu toc thai thuc hanh kho khan thong ))~.
• Adding a wildcard symbol may retrieve word variants: (( tu doanh tai thuc cac khoa phap phong ) or ( tu toc thai thuc hanh kho khan thong ))*.