Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
chat sang » chat song, chat quang, chat ban
trinh vi » trinh ve, trinh viet, trinh van
trinh va » trinh van, trinh vat, trinh ve
cong dan » cong san, cong tan, huong dan
than tap » toan tap, han tap, than cap
phan tap » phan lap, han tap, pha tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: cao chat sang - hanh ((trinh vi) OR (trinh va)) thong cong dan ((than tap) or (phan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: cao chat sang - hanh ((trinh vi) OR (trinh va)) thong cong dan ((than tap) OR (phan tap)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "cao chat sang - hanh ((trinh vi) OR (trinh va)) thong cong dan ((than tap) or (phan tap))".
• Adding a wildcard symbol may retrieve word variants: cao chat sang - hanh ((trinh vi) OR (trinh va)) thong cong dan ((than tap) or (phan tap))*.