Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
do thuc » hoc thuc, dan thuc
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
hieu vo » hieu voi, hieu va, hieu ve
sach tu » cach tu, sach ty, sach uu
tong va » thong va, trong va, tong van
va hoc » van hoc
vo do » vo co, va do, so do

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) or (sach thu)) tong va hoc. hieu vo do 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) OR (sach thu)) tong va hoc. hieu vo do thuc dan hanh ((vai cua) OR (lai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (sach thu)) tong va hoc. hieu vo do thuc dan hanh ((vai cua) or (lai cua)) tre*.