Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
pham duy » pham duc
van hanh » van thanh, ban hanh, van anh
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
duy van » duy vat, dung van
ca viet » va viet, co viet, hoa viet
lai ca » lai cua, lai cam, loai ca
x hoi » xa hoi, x ho, 5 hoi
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 ty nang ((x hoi) or (o hoi)). hieu van pham duy van hanh lai ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((x hoi) OR (o hoi)). hieu van pham duy van hanh lai ca viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((x hoi) or (o hoi)). hieu van pham duy van hanh lai ca viet*.