Perhaps you should try some spelling variations:
sach thue » sach thu, sach thieu, sach tham
thue nang » thien nang, thuat nang, thi nang
toc sach » hoc sach, doc sach, thuoc sach
dinh cuu » dinh chi
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
va hanh » van hanh, va thanh, va danh
di cuu » di cau, di cua
du va » dau va, tu va, su va

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 thue nang xa hoi. ((hieu va) or (hieu qua)) cac du va hanh ((di cuu) OR (dinh cuu)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach thue nang xa hoi. ((hieu va) OR (hieu qua)) cac du va hanh ((di cuu) OR (dinh cuu)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thue nang xa hoi. ((hieu va) or (hieu qua)) cac du va hanh ((di cuu) OR (dinh cuu)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach thue nang xa hoi. ((hieu va) or (hieu qua)) cac du va hanh ((di cuu) OR (dinh cuu)) tre*.