Perhaps you should try some spelling variations:
doanh khoa » toan khoa
thanh phan » thanh pho, thanh san, thanh toan
thanh van » thanh san, thanh toan, thanh nhan
van thanh » ban thanh, van tuan
thu mach » thu sach, thuat mach, thu hoach
mach hoc » cach hoc, dich hoc, anh hoc
long soc » lon soc, luong suc, lang son
khoa hoc » hoa hoc
va thanh » gia thanh, ban thanh, va tinh
cong so » cong san, cong hoa

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, nghien cuu ((long soc) OR (cong so)) doanh khoa hoc va thanh van thanh phan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu mach hoc tap, nghien cuu ((long soc) OR (cong so)) doanh khoa hoc va thanh van thanh phan".
• Adding a wildcard symbol may retrieve word variants: thu mach hoc tap, nghien cuu ((long soc) OR (cong so)) doanh khoa hoc va thanh van thanh phan*.