Perhaps you should try some spelling variations:
khong thuoc » khang thuoc, hong phuoc, dong thuoc
nhanh khong » nhanh chong, nganh khong, nhan khong
hoc nhanh » hoc nganh, hoc phan
thuoc tai » nuoc tai, hoc tai, thuoc ma
chuc nhan » thuc nhan, chuc nganh, chung nhan
mach hoc » cach hoc, dich hoc, anh hoc
nhan dan » phan dau, gian dan, nhan tai
cuu hoa » cuu khoa, cuu hoan, cau hoa
tai hoi » tai khoi, dai hoi, tai hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((mach hoc) or (sinh hoc)) tap, nghien cuu hoa hoc nhanh khong thuoc tai hoi chuc nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((mach hoc) OR (sinh hoc)) tap, nghien cuu hoa hoc nhanh khong thuoc tai hoi chuc nhan dan.
• Adding a wildcard symbol may retrieve word variants: tu ((mach hoc) or (sinh hoc)) tap, nghien cuu hoa hoc nhanh khong thuoc tai hoi chuc nhan dan*.