Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham duc » pham duc, pham duy, phan duc
anh hanh » anh thanh, xanh hanh, anh anh
hanh lai » hanh lam, hanh tai, thanh lap
tu sach » thu sach, su sach, te sach
ty nang » ty xang, ty hang, ly nang
ca viet » va viet, co viet, hoa viet
lai ca » lai cua, lai cam, loai ca

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 (ky nang)) xa hoi. hieu van ((cham duc) OR (cham soc)) anh hanh lai ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ky nang)) xa hoi. hieu van ((cham duc) OR (cham soc)) anh hanh lai ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ty nang) or (ky nang)) xa hoi. hieu van ((cham duc) OR (cham soc)) anh hanh lai ca viet".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ky nang)) xa hoi. hieu van ((cham duc) OR (cham soc)) anh hanh lai ca viet*.