Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, le thanh
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
cam tuc » cam xuc, nam thuc, dam thuc
va tinh » may tinh
sach ky » sac ky, sach y, sach ty
di cua » dai cua, doi cua, de cua
cua te » cua tu
cam tu » cam thu, nam tu, dam tu
nang o » nang co, nang ho, nang ro
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky nang o hoc. hieu van ((cam tuc) OR (cam tu)) ((va thanh) or (va tinh)) di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky nang o hoc. hieu van ((cam tuc) OR (cam tu)) ((va thanh) OR (va tinh)) di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky nang o hoc. hieu van ((cam tuc) OR (cam tu)) ((va thanh) or (va tinh)) di cua te".
• Adding a wildcard symbol may retrieve word variants: so sach ky nang o hoc. hieu van ((cam tuc) OR (cam tu)) ((va thanh) or (va tinh)) di cua te*.