Perhaps you should try some spelling variations:
dien nguoi » gian nguoi
lieu nguoi » lieu nguon, le nguoi, biet nguoi
dao nguoi » cho nguoi
tay nguoi » toc nguoi
mach hoc » cach hoc, dich hoc, anh hoc
cac duoc » cac nuoc, cac cuoc, cac quoc
tu mach » tu cach, tu manh, tu hach

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 ((tay nguoi) or (dao nguoi)) ) or ( tu cac duoc ((lieu nguoi) OR (dien nguoi)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu mach hoc ((tay nguoi) OR (dao nguoi)) ) OR ( tu cac duoc ((lieu nguoi) OR (dien nguoi)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu mach hoc ((tay nguoi) or (dao nguoi)) ) or ( tu cac duoc ((lieu nguoi) OR (dien nguoi)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tu mach hoc ((tay nguoi) or (dao nguoi)) ) or ( tu cac duoc ((lieu nguoi) OR (dien nguoi)) ))*.