Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
cao duc » dao duc, cao suc, giao duc
qua cao » qua cac, qua ca, qua cai
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach vay
sach 2 » sach y
di cua » dai cua, doi cua, de 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 v) or (sach 2)) nang xa hoi. hieu qua cao duc ((va danh) OR (va hanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach v) OR (sach 2)) nang xa hoi. hieu qua cao duc ((va danh) OR (va hanh)) di cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach v) or (sach 2)) nang xa hoi. hieu qua cao duc ((va danh) OR (va hanh)) di cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach v) or (sach 2)) nang xa hoi. hieu qua cao duc ((va danh) OR (va hanh)) di cua tre*.