Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, ma hoa, me hoi
thu xa » thu xac, thu xe, thu ba

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