Perhaps you should try some spelling variations:
sach van » sach han, sach va, cach van
bach van » bach dan, cach van, bach dang
dau ngoc » dau nuoc, dang ngoc, doan ngoc
van hanh » van thanh, ban hanh, van anh
nang xa » nang x, lang xa, nang ma
dau xua » dau cua, dao xuan, dau luan
cua tre » cua te, cuu tre, cua triet
vi cua » vai cua, 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: tu ((sach van) OR (bach van)) nang xa hoi. lieu va ((dau ngoc) or (dau xua)) van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach van) OR (bach van)) nang xa hoi. lieu va ((dau ngoc) OR (dau xua)) van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach van) OR (bach van)) nang xa hoi. lieu va ((dau ngoc) or (dau xua)) van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach van) OR (bach van)) nang xa hoi. lieu va ((dau ngoc) or (dau xua)) van hanh vi cua tre*.