Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
hoc doanh » hoa doanh, hoc danh, hoc dan
doanh hoa » doanh khoa, doanh hoan, danh hoa
nhan tai » hang tai, van tai, toan tai
su sach » so sach, vu sach
hoi tap » hoi dap, hoi tai, hai tap
mot hoc » mon hoc, mo hoc, mot goc
va nhan » van nhan, ca nhan, va phan
ma hoi » mai hoi, xa hoi, ma hoa

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 ((hoi tap) OR (hoc tap)), nghien cua mot hoc doanh hoa hoc ma hoi va nhan tai~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((hoi tap) OR (hoc tap)), nghien cua mot hoc doanh hoa hoc ma hoi va nhan tai".
• Adding a wildcard symbol may retrieve word variants: su sach ((hoi tap) OR (hoc tap)), nghien cua mot hoc doanh hoa hoc ma hoi va nhan tai*.