Perhaps you should try some spelling variations:
van thanh » van tuan
ban thanh » ban hanh, ban hang
thu mach » thu sach, thuat mach, thu hoach
mach hoc » cach hoc, dich hoc, anh hoc
huu toan » huu tuan, cuu toan, huy toan
toan hoc » toan khoa, van hoc, hoa hoc
bia khoa » da khoa
khoa hoc » hoa hoc
hoc bia » hoc gia, hoc giao, hoc giai
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 mach hoc tap, nhiem huu toan hoc bia khoa hoc xa hoi ((van thanh) OR (ban thanh)) van~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu mach hoc tap, nhiem huu toan hoc bia khoa hoc xa hoi ((van thanh) OR (ban thanh)) van".
• Adding a wildcard symbol may retrieve word variants: thu mach hoc tap, nhiem huu toan hoc bia khoa hoc xa hoi ((van thanh) OR (ban thanh)) van*.