Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
nganh khoa » nganh hoa, nganh khong, doanh khoa
hoa nganh » hoc nganh, khoi nganh, hoa doanh
danh nhan » doanh nhan, thanh nhan, benh nhan
van thanh » ban thanh, van tuan
sach hoc » cach hoc, sach hoi, mach hoc
cac cong » cua cong
cong hoa » dong hoa, dong hoc, hang hoa
khoa hoc » hoa hoc
su sach » so sach, vu sach
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 hoc tap, nghien cac cong hoa nganh khoa hoc ma hoi ((danh nhan) or (van thanh)) van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach hoc tap, nghien cac cong hoa nganh khoa hoc ma hoi ((danh nhan) OR (van thanh)) van.
• Adding a wildcard symbol may retrieve word variants: su sach hoc tap, nghien cac cong hoa nganh khoa hoc ma hoi ((danh nhan) or (van thanh)) van*.