Perhaps you should try some spelling variations:
khoan phap » khoan phai, khoa phau, han phap
phap thong » phap phong, phap chong, pho thong
cao khoan » cac khoan, cao khoa, tao khoang
khoan hoi » khoan nhoi, khoa hoi, khoa hoc
hoi thong » hoi thuong, hoi trong, hoa thong
thuc cao » thuoc cao, thuc co, thuc can
so cach » so sach, co cach, loi cach
cach tu » cach thuc
tu thuc » tu thuoc, thu thuc, tu thu
vu cach » va cach, ve cach, vu bach

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: (( so cach tu thuc cao khoan hoi thong ) OR ( vu cach tu thuc cao khoan phap thong ))~.
• Adding a wildcard symbol may retrieve word variants: (( so cach tu thuc cao khoan hoi thong ) or ( vu cach tu thuc cao khoan phap thong ))*.