Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cap nuoc » dat nuoc
dan thai » dang thai, dan thi, dan than
thai cuu » thai cua, tai cuc, thi cuc
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
van cap » van cau, van dap, van ca
cuu tre » cua tre, cau tren, cau treo
va dan » ca dan, va dao, va dau

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) OR (toc sach)) ky dang xa hoi. hieu van cap nuoc va dan thai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky dang xa hoi. hieu van cap nuoc va dan thai cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky dang xa hoi. hieu van cap nuoc va dan thai cuu tre*.