Perhaps you should try some spelling variations:
cach thoi » cac thoi, cach thuc, cach noi
nhan khoa » nha khoa, khuan khoa, toan khoa
nhan tain » nhan dan, nhan tao, han tai
thoi tap » toi tap, hoc tap, thoi dai
hoc nhan » hoc nhanh, nhoc nhan, hoc phan
khoa hoc » hoa hoc
nhan tai » hang tai, van tai, toan tai
tu cach » tu cac
cuu mot » cua mot, cuu mo, huu mot
mot hoc » mon hoc, mo hoc, mot goc
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: tu cach thoi tap, nghien cuu mot hoc nhan khoa hoc mai hoi va ((nhan tain) or (nhan tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach thoi tap, nghien cuu mot hoc nhan khoa hoc mai hoi va ((nhan tain) OR (nhan tai)).
• Adding a wildcard symbol may retrieve word variants: tu cach thoi tap, nghien cuu mot hoc nhan khoa hoc mai hoi va ((nhan tain) or (nhan tai))*.