Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dan hanh » dang hanh, dan khanh, dan thanh
thuc dan » thuc hanh, hoc dan, thuc vat
co thuc » do thuc, co thua, mo thuc
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
hang xa » hoang xa, hang ca, lang xa
cua tuc » cua duc, cua tu, cua thuoc
cua te » cua tu
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: toc sach tu ((hang xa) or (hang va)) hoi. hieu va co thuc dan hanh vi ((cua te) or (cua tuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tu ((hang xa) OR (hang va)) hoi. hieu va co thuc dan hanh vi ((cua te) OR (cua tuc)).
• Adding a wildcard symbol may retrieve word variants: toc sach tu ((hang xa) or (hang va)) hoi. hieu va co thuc dan hanh vi ((cua te) or (cua tuc))*.