Perhaps you should try some spelling variations:
doanh khoa » toan khoa
soc doanh » so doanh, hoa doanh, voi doanh
hanh phan » thanh phan, anh phan, hanh han
thu sach » tu sach, thuat sach, thuoc sach
sach hoc » cach hoc, sach hoi, mach hoc
cuu long » cuu cong, cuu tong, cuu nang
long soc » lon soc, luong suc, cong so
khoa hoc » hoa hoc
ban hanh » ban hang
xa thai » ca thai, a thai, da thai
do thai » do thi, toc thai

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 long soc doanh khoa hoc ((xa thai) or (do thai)) ban hanh phan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach hoc tap, nghien cuu long soc doanh khoa hoc ((xa thai) OR (do thai)) ban hanh phan.
• Adding a wildcard symbol may retrieve word variants: thu sach hoc tap, nghien cuu long soc doanh khoa hoc ((xa thai) or (do thai)) ban hanh phan*.