Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cham duc » pham duc, cham soc, pham duy
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va
duc ban » duc tan, duc van, dua ban
lai cua » hai cua, lai chau, thai cua
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 ky nang x hoi. ((hieu ve) OR (hieu van)) cham duc ban hanh ((lai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. ((hieu ve) OR (hieu van)) cham duc ban hanh ((lai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. ((hieu ve) OR (hieu van)) cham duc ban hanh ((lai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. ((hieu ve) OR (hieu van)) cham duc ban hanh ((lai cua) or (dai cua)) tre*.