Perhaps you should try some spelling variations:
su sach » so sach, vu sach
ty lang » tay lang, ty hang, tu lang
van hoe » van hoa, van hoc, van hieu
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va
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: su sach ((ty lang) OR (ty xang)) van hoe. hieu ve cam ((xuc va) or (thuc vat)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty lang) OR (ty xang)) van hoe. hieu ve cam ((xuc va) OR (thuc vat)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty lang) OR (ty xang)) van hoe. hieu ve cam ((xuc va) or (thuc vat)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty lang) OR (ty xang)) van hoe. hieu ve cam ((xuc va) or (thuc vat)) hanh vi cua tre*.