Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
ly nang » ky nang, ly hang, ly vang
van dat » van dao, van dau, dan dat
va tinh » may tinh
tinh va » tich va, trinh van, trinh vat
va cua » va chua, via cua, ca cua
cua tu » cua tuc, cua su, cua cu

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 ((ly nang) or (ty xang)) xa hoi. hieu van dat (nuoc or quoc) va tinh va cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ly nang) OR (ty xang)) xa hoi. hieu van dat (nuoc OR quoc) va tinh va cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ly nang) or (ty xang)) xa hoi. hieu van dat (nuoc or quoc) va tinh va cua tu*.