Perhaps you should try some spelling variations:
thanh hai » thanh phan, thanh hoa, thanh san
thanh lap » thanh san, phan lap, thanh van
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nuoc van » nuoc va, nuoc san, luoc van
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ve cac » va cac, vien cac
ma hoi » mai hoi, ma hoa, me hoi

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 y nang ((ma hoi) or (xa hoi)). hieu ve cac nuoc van ((thanh lap) OR (thanh hai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((ma hoi) OR (xa hoi)). hieu ve cac nuoc van ((thanh lap) OR (thanh hai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((ma hoi) or (xa hoi)). hieu ve cac nuoc van ((thanh lap) OR (thanh hai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((ma hoi) or (xa hoi)). hieu ve cac nuoc van ((thanh lap) OR (thanh hai)) cua tre*.