Perhaps you should try some spelling variations:
cong cong » cong dong, trong cong, dung cong
toan thuc » toan hoc, dan thuc, nhan thuc
tap thuc » tap tuc, tam thuc, phap thuc
ban van » ban dan, ban va, tan van
van ty » van ky, van tu, van te
ty tai » ly tai, tu tai, te tai
tuyen » truyen, quyen

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

• Performing a fuzzy search may retrieve terms with similar spellings: tuyen ((tap thuc) OR (toan thuc)) nha đe co ban van ty tai ((cong cong) or (cong (dong or dung)))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tuyen ((tap thuc) OR (toan thuc)) nha đe co ban van ty tai ((cong cong) OR (cong (dong OR dung))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tuyen ((tap thuc) OR (toan thuc)) nha đe co ban van ty tai ((cong cong) or (cong (dong or dung)))".
• Adding a wildcard symbol may retrieve word variants: tuyen ((tap thuc) OR (toan thuc)) nha đe co ban van ty tai ((cong cong) or (cong (dong or dung)))*.