Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc van » thuc vat, thuc dan, thuc hanh
nang xa » nang x, lang xa, nang ma
thuc va » thuc vat, thuc dan, thuc day
via cua » gia cua, gian cua, giau cua
y nang » ky nang, ly nang, v nang
va cao » va cac, va co, va dao
va cua » va chua, ca cua, ma cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang xa hoi. lieu va cao ((thuc van) or (thuc va)) hanh ((va cua) OR (via cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang xa hoi. lieu va cao ((thuc van) OR (thuc va)) hanh ((va cua) OR (via cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang xa hoi. lieu va cao ((thuc van) or (thuc va)) hanh ((va cua) OR (via cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. lieu va cao ((thuc van) or (thuc va)) hanh ((va cua) OR (via cua)) tre*.