Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, hieu ve
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
nam xua » nam cua, nam mua, nam qua
xua van » xua va, qua van, cua van
lai cua » hai cua, lai chau, thai cua
y nang » ky nang, ly nang, v nang

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