Perhaps you should try some spelling variations:
dang xay » dang van, van xay
hanh dao » lanh dao, thanh dat, thanh dam
hanh dai » hanh tai, vanh dai, thanh dat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
va cham » va chat, va tham
lang ha » long ha
cuu tre » cua tre, cau tren, cau treo
soc va » hoc va, loc va, doc va

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 ((dang xay) or (lang ha)) hoi. lieu va cham soc va ((hanh dai) OR (hanh dao)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((dang xay) OR (lang ha)) hoi. lieu va cham soc va ((hanh dai) OR (hanh dao)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((dang xay) or (lang ha)) hoi. lieu va cham soc va ((hanh dai) OR (hanh dao)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((dang xay) or (lang ha)) hoi. lieu va cham soc va ((hanh dai) OR (hanh dao)) cuu tre*.