Perhaps you should try some spelling variations:
tan hanh » tan thanh, tang hanh, toan hanh
te sach » toc sach
sach ly » sach y, sach lo, sach ty
ly vang » ly hang, ly van, ly quang
hieu va » lieu va
bai cua » ban cua, dai cua, bai ca
hai cua » thai cua, dai cua, hoi cua
vang x » nang x
x hoi » xa hoi, o hoi, x ho

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 ly vang x hoi. ((hieu va) OR (hieu qua)) giao duc tan hanh ((bai cua) or (hai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ly vang x hoi. ((hieu va) OR (hieu qua)) giao duc tan hanh ((bai cua) OR (hai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ly vang x hoi. ((hieu va) OR (hieu qua)) giao duc tan hanh ((bai cua) or (hai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach ly vang x hoi. ((hieu va) OR (hieu qua)) giao duc tan hanh ((bai cua) or (hai cua)) tre*.