Perhaps you should try some spelling variations:
nganh khong » nganh cong, nhanh chong, nganh nong
nganh khoa » nganh hoa, doanh khoa, anh khoa
mach hoc » cach hoc, dich hoc, anh hoc
cuu cong » cua cong, thu cong, cac cong
cong hoa » dong hoa, dong hoc, hang hoa
gian dan » gian lang
tu mach » tu cach, tu manh, tu hach
va gian » va gianh, van gian, va giai
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 mach hoc tap, nghien cuu cong hoa ((nganh khoa) or (nganh khong)) hoc ma hoi va gian dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu mach hoc tap, nghien cuu cong hoa ((nganh khoa) OR (nganh khong)) hoc ma hoi va gian dan.
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien cuu cong hoa ((nganh khoa) or (nganh khong)) hoc ma hoi va gian dan*.