Perhaps you should try some spelling variations:
khoan khau » khoanh khac, khoa kham, khoa phau
khau thong » khau thuong, khap thong, khau tong
pho thong » he thong
sach thai » sach tham, sac thai, sach tai
toc sach » hoc sach, doc sach, thuoc sach
sach tri » sach tai, sach tren, sach bai
tri thuc » tri tue
thuc cac » thuc cach, phuc cac, thac cac
thai tuc » thai thuc, thai thuy, thai hoc
hop pho » hoc pho, hop cho, hop khoa
su sach » so sach, vu sach
tuc cac » tu cac, tich cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( toc sach tri thuc cac hop pho thong ) or ( su sach thai tuc cac khoan khau thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach tri thuc cac hop pho thong ) OR ( su sach thai tuc cac khoan khau thong )).
• Adding a wildcard symbol may retrieve word variants: (( toc sach tri thuc cac hop pho thong ) or ( su sach thai tuc cac khoan khau thong ))*.