Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach dao » lanh dao
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
phan dau » phan tu, hang dau
dao tap » dao tao, dao tay, dao gap
dan hoa » danh hoa, dan hoat, dan khoa
dai hoi » dai hoc, dai hai, dai moi
va phan » van phan, va phat, va phap
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: toc sach dao tap, nghien cuu cong hoc dan hoa hoc ((ma hoi) or (dai hoi)) va phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach dao tap, nghien cuu cong hoc dan hoa hoc ((ma hoi) OR (dai hoi)) va phan dau.
• Adding a wildcard symbol may retrieve word variants: toc sach dao tap, nghien cuu cong hoc dan hoa hoc ((ma hoi) or (dai hoi)) va phan dau*.