Perhaps you should try some spelling variations:
cach thoi » cac thoi, cach thuc, cach noi
cuu dong » cuu cong, cuu tong, cuu long
dong luc » nang luc
luc hanh » luc canh, luu hanh, duc hanh
hanh hoa » thanh hoa, khanh hoa, hang hoa
phan van » pham van, thanh van, luan van
cac thu » cach thuc, cac thoi
vo phan » co phan, va phan, so phan
hoa vo » hoa co

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((cach thoi) or (cac thu)) tap, nghien cuu dong luc hanh hoa hoc ma hoa vo phan van~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((cach thoi) OR (cac thu)) tap, nghien cuu dong luc hanh hoa hoc ma hoa vo phan van.
• Adding a wildcard symbol may retrieve word variants: tu ((cach thoi) or (cac thu)) tap, nghien cuu dong luc hanh hoa hoc ma hoa vo phan van*.