Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
thanh toan » thanh hoa, thanh san, tinh toan
hoang hoa » hang hoa, hoang ha, hoang thoan
dan thanh » dang thanh, danh thanh, ban thanh
sach moi » sach doi, sach hoi, bach mai
cong hoc » dong hoc, cong hoa, cong coc
hoan hoc » hoa hoc, toan hoc, khoan hoi
su sach » so sach, vu sach
moi tap » moi tai, toi tap
mai hoi » mai khoi, dai hoi, lai hoi
hoi dan » hoa dan, hoi dap, thoi dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach moi tap, nghien thu cong hoc dan ((hoan hoc) or (hoang hoa)) mai hoi dan thanh toan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach moi tap, nghien thu cong hoc dan ((hoan hoc) OR (hoang hoa)) mai hoi dan thanh toan.
• Adding a wildcard symbol may retrieve word variants: su sach moi tap, nghien thu cong hoc dan ((hoan hoc) or (hoang hoa)) mai hoi dan thanh toan*.