Perhaps you should try some spelling variations:
khoan khau » khoanh khac, khoa kham, khoa phau
khau thong » khau thuong, khap thong, khau tong
khoa thong » hoa thong, thoai thong, pho thong
tri truoc » tri thuoc, gi truoc, thi truc
truoc dam » truoc nam, thuoc dac, truc dai
khoa khoa » hoa khoa, khuan khoa, khoa hoc
sanh tri » thanh tri, dinh tri, minh tri
tri thuc » tri tue
thuc cac » thuc cach, tuc cac, phuc cac
sach tri » sach tai, sach tren, sach truc
dam khoa » da khoa, nam khoa, dac khoa
so sanh » do sanh
tu sach » thu sach, su sach, te sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( so sanh tri thuc cac khoan khau thong ) or ( tu sach tri truoc dam khoa khoa thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sanh tri thuc cac khoan khau thong ) OR ( tu sach tri truoc dam khoa khoa thong )).
• Adding a wildcard symbol may retrieve word variants: (( so sanh tri thuc cac khoan khau thong ) or ( tu sach tri truoc dam khoa khoa thong ))*.