Perhaps you should try some spelling variations:
nghien thu » nghiem thuc, nghiep thuc, nghien cuu
nganh khoa » nganh hoa, nganh khong, doanh khoa
sach nuoc » sach duoc, cac nuoc, bach tuoc
hoc nganh » hoc nhanh
tinh hoc » sinh hoc, tin hoc, hinh hoc
cong hoc » dong hoc, cong hoa, cong coc
khoa hoc » hoa hoc
cac khoi » cac thoi, cac khoan, cach thoi
nhan tai » hang tai, van tai, toan tai
hoc cac » hoc cao
khoi ca » khoi can, khoi cua, khoi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach nuoc) or (tinh hoc)) tap, nghien thu cong hoc nganh khoa hoc cac khoi ca nhan tai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach nuoc) OR (tinh hoc)) tap, nghien thu cong hoc nganh khoa hoc cac khoi ca nhan tai.
• Adding a wildcard symbol may retrieve word variants: tu ((sach nuoc) or (tinh hoc)) tap, nghien thu cong hoc nganh khoa hoc cac khoi ca nhan tai*.