Perhaps you should try some spelling variations:
thu canh » thuc hanh, thu cong, thu ban
thoi dai » hoc dai, hoi dap
cuu toan » cuu hoan, cua toan, huu toan
toan hoc » toan khoa, van hoc, hoa hoc
dan khoa » dang khoa, da khoa, san khoa
khoa hoc » hoa hoc
van nhan » van phan, van thanh, danh nhan
nhan tai » hang tai, van tai, toan tai
hoi dan » hoa dan, hoi dap
hai van » thai van, ha van, hai tan
hoc xa » hoc ma
xa hai » xa thai, xua hai, xa hoi

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) OR (hoi dan)), nghien cuu toan hoc dan khoa hoc xa hai van nhan tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu canh ((thoi dai) OR (hoi dan)), nghien cuu toan hoc dan khoa hoc xa hai van nhan tai".
• Adding a wildcard symbol may retrieve word variants: thu canh ((thoi dai) OR (hoi dan)), nghien cuu toan hoc dan khoa hoc xa hai van nhan tai*.