Perhaps you should try some spelling variations:
cua viet » ca viet, cua vat, cua dieu
kinh vai » kinh hai, kinh va, kinh van
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac
xuc va » duc va, tuc va, xac va
y nang » ky nang, ly nang, v nang
luc va » duc va, tuc va, loc va
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 y nang o hoi. hieu ve cac ((xuc va) or (luc va)) kinh vai ((cua viet) OR (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hoi. hieu ve cac ((xuc va) OR (luc va)) kinh vai ((cua viet) OR (hoa viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hoi. hieu ve cac ((xuc va) or (luc va)) kinh vai ((cua viet) OR (hoa viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. hieu ve cac ((xuc va) or (luc va)) kinh vai ((cua viet) OR (hoa viet))*.