Perhaps you should try some spelling variations:
cong thuoc » cong thuc, dong thuoc, long thuoc
cach thoi » cac thoi, cach thuc, cach noi
thoi dap » hoi dap, thoi dai, thi dap
thuoc ma » hoc ma, duoc ma
quan van » luan van, quan va, quan luan
tu cach » tu cac
va quan » van quan, tac quan, hai quan
ma hoi » mai hoi, xa hoi, ma hoa

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cach thoi dap, nghien cuu ((khoa hoc) OR (hoa hoc)) thanh cong thuoc ma hoi va quan van~".
• Adding a wildcard symbol may retrieve word variants: tu cach thoi dap, nghien cuu ((khoa hoc) OR (hoa hoc)) thanh cong thuoc ma hoi va quan van*.