Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
tan hanh » tan thanh, tang hanh, toan hanh
hanh lai » hanh lam, hanh tai, thanh lap
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
lai cua » dai cua, hai cua, lai chau
x hoi » xa hoi, x ho
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 ty nang ((((x hoi) OR (5 hoi))) or (o hoi)). hieu van pham duc tan hanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ((((x hoi) OR (5 hoi))) OR (o hoi)). hieu van pham duc tan hanh lai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty nang ((((x hoi) OR (5 hoi))) or (o hoi)). hieu van pham duc tan hanh lai cua viet*".