Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, le thanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va tinh » may tinh
luu tre » luu tru, cuu tre, luy tre
ve cac » va cac, vien cac
nang o » nang co, nang ho, nang ro
vi luu » vi lua
ve bao » te bao, va bao
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 ((ve cac) or (ve bao)) duc ((va thanh) OR (va tinh)) vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang o hoi. hieu ((ve cac) OR (ve bao)) duc ((va thanh) OR (va tinh)) vi luu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang o hoi. hieu ((ve cac) or (ve bao)) duc ((va thanh) OR (va tinh)) vi luu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang o hoi. hieu ((ve cac) or (ve bao)) duc ((va thanh) OR (va tinh)) vi luu tre*.