Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh de » hanh ve, hanh kem
cao tuc » dao tuc, cao duc, cao suc
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
tuc va » thuc va, truc va, tuc xa
va cao » va cac, va co, va dao

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

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