Perhaps you should try some spelling variations:
hieu ve » hieu va, hieu van
duc van » duc va, duc tan, duc manh
ve giao » te giao, viet giao, van giao
tu sach » thu sach, su sach, te sach
mai hoi » mai khoi, dai hoi, lai hoi
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
cua tre » cua te, cuu tre, cua triet

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 ((ty nang) or (ty hang)) mai hoi. hieu ve giao duc van ((thanh pho) or (dung tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty hang)) mai hoi. hieu ve giao duc van ((thanh pho) OR (dung tai)) cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty hang)) mai hoi. hieu ve giao duc van ((thanh pho) or (dung tai)) cua tre*.