Perhaps you should try some spelling variations:
nganh dong » nganh cong, nhanh dong, nganh nong
hoc nganh » hoc nhanh
sach hoc » cach hoc, sach hoi, mach hoc
dong hoi » dong hoc, dong hoa, dong co
van nhan » van phan, van thanh, danh nhan
nhan tai » hang tai, van tai, toan tai
bo sach » co sach, hoc sach
cuu mot » cua mot, cuu mo, cuu vuot
huu mot » huy mot, hieu mot, chua mot
hoi tra » hoi trac, hoi tri, hoi thao
tra hai » tran hai, tra ha, ta hai
hai van » thai van, ha van, hai tan

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

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach hoc tap, nghien ((cuu mot) or (huu mot)) hoc nganh dong hoi tra hai van nhan tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach hoc tap, nghien ((cuu mot) OR (huu mot)) hoc nganh dong hoi tra hai van nhan tai.
• Adding a wildcard symbol may retrieve word variants: bo sach hoc tap, nghien ((cuu mot) or (huu mot)) hoc nganh dong hoi tra hai van nhan tai*.