Perhaps you should try some spelling variations:
doanh hoan » doanh doanh, doanh khoa, doanh nhan
doanh hoa » doanh khoa, danh hoa, doanh ha
hut tinh » hut binh, huu tinh, huy tinh
tinh hoc » sinh hoc, tin hoc, hinh hoc
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
dan nhan » danh nhan, dan chan, van nhan
nhan va » nhan tai, nhan dan, nhan tao
ma hoc » va hoc, ma hoa, mo hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: hut tinh hoc tap, nghien cuu cong hoc ((doanh hoa) OR (doanh hoan)) hoc ma hoc dan nhan va~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hut tinh hoc tap, nghien cuu cong hoc ((doanh hoa) OR (doanh hoan)) hoc ma hoc dan nhan va".
• Adding a wildcard symbol may retrieve word variants: hut tinh hoc tap, nghien cuu cong hoc ((doanh hoa) OR (doanh hoan)) hoc ma hoc dan nhan va*.