Perhaps you should try some spelling variations:
vinh cuu » dinh cuu, sinh cua, dinh cu
su sach » so sach, vu sach
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
va cam » va cham, va cac, va cai
va cao » va cac, va co, va dao
vi cuu » vi luu
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 cam) OR (va cao)) duc va hanh ((vi cuu) or (vinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang o hoi. hieu ((va cam) OR (va cao)) duc va hanh ((vi cuu) OR (vinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang o hoi. hieu ((va cam) OR (va cao)) duc va hanh ((vi cuu) or (vinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: su sach y nang o hoi. hieu ((va cam) OR (va cao)) duc va hanh ((vi cuu) or (vinh cuu)) tre*.