Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghiep cay, nghiep bac
cong toan » cong tan, cong hoan, cong tuan
doanh hoa » doanh khoa, doanh hoan, danh hoa
sach hoi » sach doi, sach moi, cach thoi
nhan dan » phan dau, gian dan, nhan tai
te sach » toc sach
hoi tap » hoi dap, hoc tap, hoi tai
hoc dai » hoc dan
dai son » dai so, doi song, thai son
son ca » song ca, son la, son ha

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach hoi tap, ((nghien cac) OR (nghien cuu)) cong toan doanh hoa hoc dai son ca nhan dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach hoi tap, ((nghien cac) OR (nghien cuu)) cong toan doanh hoa hoc dai son ca nhan dan".
• Adding a wildcard symbol may retrieve word variants: te sach hoi tap, ((nghien cac) OR (nghien cuu)) cong toan doanh hoa hoc dai son ca nhan dan*.