Perhaps you should try some spelling variations:
thang nguoi » thanh nguoi, thong nguoi, tang nguoi
thai nguoi » phai nguoi, thanh nguoi, thuat nguoi
hach toan » thanh toan, manh toan
tay nguoi » toc nguoi, dao nguoi
ky nguoi » ly nguoi, ke nguoi, lay nguoi
tu hach » tu hanh, tu cach, tu sach
tu hoc » te hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu hach toan ((thai nguoi) or (thang nguoi)) ) or ( tu hoc nuoc ((ky nguoi) OR (tay nguoi)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu hach toan ((thai nguoi) OR (thang nguoi)) ) OR ( tu hoc nuoc ((ky nguoi) OR (tay nguoi)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu hach toan ((thai nguoi) or (thang nguoi)) ) or ( tu hoc nuoc ((ky nguoi) OR (tay nguoi)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tu hach toan ((thai nguoi) or (thang nguoi)) ) or ( tu hoc nuoc ((ky nguoi) OR (tay nguoi)) ))*.