Perhaps you should try some spelling variations:
thien van » thi van
thu sach » thuat sach, thuoc sach, thu hoach
thuc day » thuc dan, thuc vat
tu sach » su sach, te sach, tu cach
hanh va » hang va, hanh vi
van cam » van nam, van lam, van cau
xang xa » lang xa, mang xa, ang xa
tu xang » ty xang, tu lang, tu quang
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
va cua » va chua, via cua, ca 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) OR (thu sach)) tu xang xa hoi. thien van cam ((xuc va) or (thuc day)) hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) tu xang xa hoi. thien van cam ((xuc va) OR (thuc day)) hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) tu xang xa hoi. thien van cam ((xuc va) or (thuc day)) hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) tu xang xa hoi. thien van cam ((xuc va) or (thuc day)) hanh va cua tre*.