Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dang duc » dang quoc, dao duc, dang su
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
va dang » van dang, va nang, va lang
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
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: su sach y nang o hoi. hieu va dang duc van hanh vi ((cua tre) OR (cua triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang o hoi. hieu va dang duc van hanh vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: su sach y nang o hoi. hieu va dang duc van hanh vi ((cua tre) OR (cua triet))*.