Perhaps you should try some spelling variations:
pham duy » pham duc
hieu van » hieu va, thien van, lieu va
cham duc » pham duc, cham soc, phan duc
van hanh » van thanh, ban hanh, van anh
hai cua » thai cua, dai cua, hoi cua
lai cua » dai cua, lai chau, thai cua
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
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) OR (hai cua)) 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) OR (hai cua)) 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) OR (hai cua)) 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) OR (hai cua)) viet*.