Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan, thuc day
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
sach ly » sach y, sach lo, sach ty
van cam » van nam, van lam, van cau
nang xa » nang x, lang xa, nang ma
ly nang » ky nang, ly hang, ly vang
luc va » duc va, tuc va, loc va

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