Perhaps you should try some spelling variations:
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
sach thu » sach thue, sach thieu, sach tham
te sach » toc sach
co thuc » do thuc, co thua, mo thuc
bai cua » ban cua, bai ca, hai cua
hieu va » lieu va, hieu qua
dong ha » dong hoa, dong va, dong hoc
dong xa » dong xay, duong xa, dong va
va co » vo co

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 thu ((dong xa) OR (dong ha)) hoi. hieu va co thuc dan hanh ((bai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thu ((dong xa) OR (dong ha)) hoi. hieu va co thuc dan hanh ((bai cua) OR (dai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thu ((dong xa) OR (dong ha)) hoi. hieu va co thuc dan hanh ((bai cua) or (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: te sach thu ((dong xa) OR (dong ha)) hoi. hieu va co thuc dan hanh ((bai cua) or (dai cua)) tre*.