Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
tan hanh » tan thanh, tang hanh, toan hanh
thai cua » than cua, tai cuc, tri cua
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
hai cua » dai cua, hoi cua, lai cua
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky nang xa hoi. ((hieu va) or (hieu van)) cam duc tan hanh ((hai cua) OR (thai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang xa hoi. ((hieu va) OR (hieu van)) cam duc tan hanh ((hai cua) OR (thai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang xa hoi. ((hieu va) or (hieu van)) cam duc tan hanh ((hai cua) OR (thai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang xa hoi. ((hieu va) or (hieu van)) cam duc tan hanh ((hai cua) OR (thai cua)) tre*.