Perhaps you should try some spelling variations:
nghien huu » nghien cuu, nguyen huu, nhiem huu
hoc doanh » hoa doanh, hoc danh, hoc dan
doanh hoa » doanh khoa, doanh hoan, danh hoa
sach hoi » sach moi, cach thoi, hoach hoi
sach doi » sach moi, sach dao, sach bai
cua ngan » cua ban, vu ngan, cua dan
ngan tai » nganh tai, nhan tai, gan tai
huu mot » cuu mot, huy mot, hieu mot
mot hoc » mon hoc, mo hoc, mot goc
hoi cua » hoi chuc
hoc xa » hoc ma

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc ((sach hoi) OR (sach doi)) tai, nghien huu mot hoc doanh hoa hoc xa hoi cua ngan tai~".
• Adding a wildcard symbol may retrieve word variants: thuoc ((sach hoi) OR (sach doi)) tai, nghien huu mot hoc doanh hoa hoc xa hoi cua ngan tai*.