Perhaps you should try some spelling variations:
cach thoi » cach thuc, cach noi
cac thoi » cac toi, cac hop, cac tro
cuu cong » cua cong, thu cong, cac cong
cong coc » cong cuoc, cong cac, cong co
coc toan » ngoc toan, coc khoan, quoc toan
toan hoa » toan khoa, toan hoat, toan hoc
gian dan » gian lang
va gian » va gianh, van gian, va giai
hoc xa » hoc ma

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((cach thoi) OR (cac thoi)) tap, nghien cuu cong coc toan hoa hoc xa hoi va gian dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((cach thoi) OR (cac thoi)) tap, nghien cuu cong coc toan hoa hoc xa hoi va gian dan".
• Adding a wildcard symbol may retrieve word variants: tu ((cach thoi) OR (cac thoi)) tap, nghien cuu cong coc toan hoa hoc xa hoi va gian dan*.