Perhaps you should try some spelling variations:
chuyen triet » chuyen tiep, chuyen tren, chuyen tri
chet triet » thuyet triet
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, va tinh
thanh la » thanh lap, thanh lam, thanh lan
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
van cau » van dau, van hau, van chat
cau duc » cao duc, cau luc, chu duc
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky nang o hoi. hieu van cau duc va thanh la ((chet triet) OR (chuyen triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu van cau duc va thanh la ((chet triet) OR (chuyen triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu van cau duc va thanh la ((chet triet) OR (chuyen triet))*.