Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
canh thoi » cach thoi, hanh thoi, anh tho
thu canh » thuc hanh, thu cong, thu ban
thoi dai » hoc dai, hoi dap, hoi dan
huu toan » huu tuan, cuu toan, huy toan
toan hoc » toan khoa, van hoc, tin hoc
hoc toan » hoc tan, hop toan, hoa toan
toan hoa » toan khoa, toan hoat, toan ho
nhan tai » hang tai, van tai, toan tai
xa thai » ca thai, a thai, da thai
xa hai » xua hai, xa hoi, xa dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu canh thoi dai, nghien huu toan hoc toan hoa hoc ((xa hai) OR (xa thai)) doanh nhan tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu canh thoi dai, nghien huu toan hoc toan hoa hoc ((xa hai) OR (xa thai)) doanh nhan tai".
• Adding a wildcard symbol may retrieve word variants: thu canh thoi dai, nghien huu toan hoc toan hoa hoc ((xa hai) OR (xa thai)) doanh nhan tai*.