Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
xuc van » duc van, luc van, vuc van
lai cua » hai cua, lai chau, thai cua

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