Perhaps you should try some spelling variations:
phap thong » phap phong, phap chong, pho thong
cong khoa » cong hoa, con khoa, dong khoa
khoa phap » khoa phau, khoan phai, khong phap
sach thu » sach thue, sach thieu, sach tham
tuc cong » duc cong, toc cong, tuc vong
tu sach » thu sach, su sach, te sach
tuc dan » thuc dan, thuc day, tung dan
khoa he » khoa hoc, khong he, khoa 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 thu tuc dan ((khoa he) OR (hoa he)) thong ) or ( tu sach thu tuc cong khoa phap thong ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu sach thu tuc dan ((khoa he) OR (hoa he)) thong ) OR ( tu sach thu tuc cong khoa phap thong )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu sach thu tuc dan ((khoa he) OR (hoa he)) thong ) or ( tu sach thu tuc cong khoa phap thong ))".
• Adding a wildcard symbol may retrieve word variants: (( tu sach thu tuc dan ((khoa he) OR (hoa he)) thong ) or ( tu sach thu tuc cong khoa phap thong ))*.