Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thuc cua » hoc cua, thuc va
dang xa » dang xay, lang xa, dang ha
sach ky » sac ky, sach y, sach ty
thuc ca » thuc can, thuc cao, thuc va
ky dang » ky nang, ky danh
dan vai » dan va, dan tai, dan vat
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo

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 ky dang xa hoi. ((lieu va) or (hieu qua)) nam ((thuc ca) OR (thuc cua)) dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang xa hoi. ((lieu va) OR (hieu qua)) nam ((thuc ca) OR (thuc cua)) dan vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang xa hoi. ((lieu va) or (hieu qua)) nam ((thuc ca) OR (thuc cua)) dan vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang xa hoi. ((lieu va) or (hieu qua)) nam ((thuc ca) OR (thuc cua)) dan vai cuu tre*.