Perhaps you should try some spelling variations:
canh thoi » cach thoi, hanh thoi, anh thi
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
tan nhan » tran nhan, tao nhan, van nhan
nhan tai » hang tai, van tai, toan tai
anh tho » anh khoa, anh thuc
hai tan » hai van, hai quan
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) OR (anh tho)) dai, nghien cuu toan hoc dan khoa hoc xa hai tan nhan tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((canh thoi) OR (anh tho)) dai, nghien cuu toan hoc dan khoa hoc xa hai tan nhan tai".
• Adding a wildcard symbol may retrieve word variants: thu ((canh thoi) OR (anh tho)) dai, nghien cuu toan hoc dan khoa hoc xa hai tan nhan tai*.