Perhaps you should try some spelling variations:
cach thoi » cac thoi, cach thuc, cach noi
toc cach » hoc cach, toc sach, truoc cach
thoi tap » toi tap, hoc tap, thoi dai
cuu toan » cuu hoan, cua toan, huu toan
hoc toan » hop toan, hoa toan, hoc than
khoa hoc » hoa hoc
nhan dan » phan dau, gian dan, nhan tai
hoc tan » hoc tang, hoc dan, hoc tap
hoc xa » hoc ma
hoi ca » hoi cua, hoi cac, hoi cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc cach thoi tap, nghien cuu toan ((hoc toan) OR (hoc tan)) khoa hoc xa hoi ca nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc cach thoi tap, nghien cuu toan ((hoc toan) OR (hoc tan)) khoa hoc xa hoi ca nhan dan".
• Adding a wildcard symbol may retrieve word variants: toc cach thoi tap, nghien cuu toan ((hoc toan) OR (hoc tan)) khoa hoc xa hoi ca nhan dan*.