Perhaps you should try some spelling variations:
nghien cac » nghiep cach, nghien cuu, nghiep cay
toc sach » hoc sach, doc sach, thuoc sach
sach dao » lanh dao
cac cong » cua cong
coc phan » hoc phan, cac phan, doc phan
nang dan » nang danh, nong dan, nang dau
dao tai » dao thai, dao tao, cao tai
hoc mai » hoc ma, hoc dai, hoc bai
mai hoi » mai khoi, dai hoi, lai hoi
chuc » thuc, chu, chua

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 dao tai, nghien cac cong ((coc phan) OR (co phan)) hoa hoc mai hoi chuc nang dan~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach dao tai, nghien cac cong ((coc phan) OR (co phan)) hoa hoc mai hoi chuc nang dan".
• Adding a wildcard symbol may retrieve word variants: toc sach dao tai, nghien cac cong ((coc phan) OR (co phan)) hoa hoc mai hoi chuc nang dan*.