Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
van nang » van quang, van ban, van dong
doc sach » toc sach, nuoc sach, dac sac
va hanh » van hanh, va thanh, va danh
cam luc » cam xuc, cau luc
hieu va » lieu va, hieu qua
va nang » da nang, cam nang, kha nang
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc 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: ((hoc sach) or (doc sach)) ((va nang) OR (van nang)) xa hoi. hieu va cam luc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (doc sach)) ((va nang) OR (van nang)) xa hoi. hieu va cam luc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (doc sach)) ((va nang) OR (van nang)) xa hoi. hieu va cam luc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (doc sach)) ((va nang) OR (van nang)) xa hoi. hieu va cam luc va hanh vi cua tre*.