Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
vai cuu » vai cua
dan vai » dan va, dan tai, dan vat
thuc ca » thuc cua, thuc can, thuc cao
hieu va » hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo
ca dan » cac dan, ca dao

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) or (doc sach)) ky lang xa hoi. ((hieu va) or (lieu va)) am thuc ca dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky lang xa hoi. ((hieu va) OR (lieu va)) am thuc ca dan vai cuu tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ky lang xa hoi. ((hieu va) or (lieu va)) am thuc ca dan vai cuu tre*.