Perhaps you should try some spelling variations:
dong hoc » dong co, dong luc
van hanh » van thanh, ban hanh, van anh
chieu tu » chieu tro, lieu tu, chu tu
dong hoa » dong co
so sach » bo sach, co sach, hoc sach
hanh va » hang va, hanh vi
xuc van » duc van, luc van, vuc van
so sanh » do sanh
cua tre » cua te, cuu tre, cua triet
tu cam » tu cham, tu cac, tu nam
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: ((so sach) or (so sanh)) ky ((dong hoa) OR (dong hoc)) hoi. chieu tu cam xuc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (so sanh)) ky ((dong hoa) OR (dong hoc)) hoi. chieu tu cam xuc van hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) or (so sanh)) ky ((dong hoa) OR (dong hoc)) hoi. chieu tu cam xuc van hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) or (so sanh)) ky ((dong hoa) OR (dong hoc)) hoi. chieu tu cam xuc van hanh va cua tre*.