Perhaps you should try some spelling variations:
khoa doanh » hoa doanh, cho doanh, khoa dang
hoan khoa » toan khoa, hoa khoa, han khoa
doanh hoa » doanh khoa, doanh hoan, danh hoa
thu sach » tu sach, thuat sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
cuu hoan » luu hoang, cuu van, cuu khoa
nhan dan » phan dau, nhan tai
gian dan » gian lang
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: thu sach hoc tap, nghien cuu hoan khoa doanh hoa hoc xa hoi va ((nhan dan) OR (gian dan))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach hoc tap, nghien cuu hoan khoa doanh hoa hoc xa hoi va ((nhan dan) OR (gian dan))".
• Adding a wildcard symbol may retrieve word variants: thu sach hoc tap, nghien cuu hoan khoa doanh hoa hoc xa hoi va ((nhan dan) OR (gian dan))*.