Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
ly quang » le quang, vu quang
va thanh » gia thanh, va tinh, le thanh
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
tu sach » thu sach, su sach, te sach
ty nang » ky nang, ty xang, ty hang
va cua » va chua, via cua, ca cua
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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 ((ty nang) or (ly quang)) x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ly quang)) x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ly quang)) x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua te".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ly quang)) x hoi. hieu van cam duc ((va thanh) OR (ban thanh)) va cua te*.