Perhaps you should try some spelling variations:
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
te sach » toc sach
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
co thuc » do thuc, co thua, mo thuc
hieu vo » hieu voi, hieu va, hieu ve
sach tu » sach thu, cach tu, sach ty
tu tong » tu tuong, tu trong, tu dong
va hoc » van hoc
va hoi » xa hoi, va hoa

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