Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham duc » pham duc, cham soc, phan duc
cua viet » ca viet, cua vat, cua dieu
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
ty nang » ky nang, ty xang, ty hang
sach ty » sach y, sach tu, sach thu
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 x hoi. hieu van ((cham duc) or (pham duy)) van hanh lai ((cua viet) OR (hoa viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang x hoi. hieu van ((cham duc) OR (pham duy)) van hanh lai ((cua viet) OR (hoa viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang x hoi. hieu van ((cham duc) or (pham duy)) van hanh lai ((cua viet) OR (hoa viet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang x hoi. hieu van ((cham duc) or (pham duy)) van hanh lai ((cua viet) OR (hoa viet))*.