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
van hanh » van thanh, ban hanh, van anh
dinh cuu » dinh chi
nang xa » nang x, lang xa, nang ma
hieu va » lieu va
du van » duy van, duc van, tu van
di cuu » di cau, di cua

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 van 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 van 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 van hanh ((di cuu) or (dinh cuu)) tre*.