Perhaps you should try some spelling variations:
khoan khau » khoanh khac, khoa kham, khoa phau
khau thong » khau thuong, khap thong, khau tong
dan khoan » dan khoa, dai khoang, toan khoan
khoan pho » khoan nhoi, khoan phai, khoan hoi
pho thong » he thong
sach tai » sach bai, sach tham, sach dao
thuc dan » thuc hanh, hoc dan, thuc vat
tu sach » thu sach, su sach, te sach
tai tuc » thai tuc, tai cuc, tai tu
tuc cac » tu cac, tich cac
sach tu » sach thu, cach tu, sach ty
tu thuc » tu thuoc, thu thuc, tu thu

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

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