Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
chuc nong » chuc nang, chuc cong, chuc trong
toc sach » hoc sach, doc sach, thuoc sach
cac cong » cua cong
cong coc » cong cuoc, cong cac, cong co
coc phan » co phan, hoc phan, cac phan
phan hoa » phan loai, phan phoi, phan hong
nong dan » cong dan, nong san, nguong dan
hoc anh » hoc nganh, hoc nhanh, ngoc anh
dao tai » dao thai, dao tao, cao tai
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (hoc anh)) dao tai, nghien cac cong coc phan hoa hoc mai hoi chuc nong dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc anh)) dao tai, nghien cac cong coc phan hoa hoc mai hoi chuc nong dan.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc anh)) dao tai, nghien cac cong coc phan hoa hoc mai hoi chuc nong dan*.