Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
cam luc » cam xuc, cau luc
vai cua » dai cua, hai cua, lai cua
va hanh » va thanh, va danh, ban hanh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
ve cam » ve cham, ve cac, va cam

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 ((ky lang) OR (ky dang)) xa hoi. hieu ve cam luc ((va hanh) or (van hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky lang) OR (ky dang)) xa hoi. hieu ve cam luc ((va hanh) OR (van hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky lang) OR (ky dang)) xa hoi. hieu ve cam luc ((va hanh) or (van hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky lang) OR (ky dang)) xa hoi. hieu ve cam luc ((va hanh) or (van hanh)) vai cua tre*.