Perhaps you should try some spelling variations:
nghien cua » nghien cuu, nghiep cua, nghiep vua
cong hoc » dong hoc, cong hoa, cong coc
tan khoa » toan khoa, tran khoa, san khoa
khoa hoc » hoa hoc
dan nhan » danh nhan, dan chan, van nhan
te mach » te sach, tim mach, tao mach
ke mach » ke hoach
hoc tan » hoc tang, hoc dan, hoc tai
hoc dai » hoc dan
dai hoi » dai hoc, dai hai, dai moi
hoi dan » hoa dan, hoc dan, hoi dap
nhan va » nhan tai, nhan dan, nhan tao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te mach) or (ke mach)) hoc tap, nghien cua cong hoc tan khoa hoc dai hoi dan nhan va~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te mach) OR (ke mach)) hoc tap, nghien cua cong hoc tan khoa hoc dai hoi dan nhan va.
• Adding a wildcard symbol may retrieve word variants: ((te mach) or (ke mach)) hoc tap, nghien cua cong hoc tan khoa hoc dai hoi dan nhan va*.