Perhaps you should try some spelling variations:
cach thoi » cac thoi, cach thuc, cach noi
ngan bang » ngan hang, gan bang, ngan danh
thoi tap » toi tap, hoc tap, thoi dai
cuu cong » cua cong, thu cong, cac cong
cong boc » cong bo, cong coc, cong uoc
boc ngan » bo ngan, hoc nganh, buoi ngan
bang hoc » nang hoc, mang hoc, quang hoc
hoi danh » hop danh, hoi dan, hoc danh
nhan tai » hang tai, van tai, toan tai
tu cach » tu cac
nhan va » nhan dan, nhan tao, phan van
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: tu cach thoi tap, nghien cuu cong boc ngan bang hoc ma hoi danh ((nhan va) or (nhan tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu cach thoi tap, nghien cuu cong boc ngan bang hoc ma hoi danh ((nhan va) OR (nhan tai)).
• Adding a wildcard symbol may retrieve word variants: tu cach thoi tap, nghien cuu cong boc ngan bang hoc ma hoi danh ((nhan va) or (nhan tai))*.