Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach hoi » sach doi, sach moi, cach thoi
khoa hoc » hoa hoc
nhan dan » phan dau, gian dan, nhan tai
hoi tap » hoi dap, hoc tap, hoi tai
cuu mot » cua mot, cuu mo, huu mot
hoc tan » hoc tang, hoc tap, hoc tai
va nhan » van nhan, ca nhan, va phan
hoc xa » hoc ma

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

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