Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thai cua » than cua, tai cuc, tri cua
van hanh » van thanh, ban hanh, van anh
va hanh » va thanh, va danh, ban hanh
bao duc » dao duc, bao luc, cao duc
van bao » van ban, van dao
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, cua triet

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

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