Perhaps you should try some spelling variations:
hieu cao » chieu cao, hieu cac, hieu ca
cao chao » chao chao, cao chat, cao cho
te sach » toc sach
cu lang » cua lang, tu lang, xu lang
vu lang » va lang, vu dang, tu lang
cua tre » cua te, cuu tre, cua triet
dao va » dao van, tao va, do va
va cua » va chua, via cua, ca cua
xu va » xu van, su va, vu va

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((vu lang) OR (cu lang)) xa hoi. hieu cao chao ((xu va) or (tu va)) dao va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((vu lang) OR (cu lang)) xa hoi. hieu cao chao ((xu va) OR (tu va)) dao va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((vu lang) OR (cu lang)) xa hoi. hieu cao chao ((xu va) or (tu va)) dao va cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((vu lang) OR (cu lang)) xa hoi. hieu cao chao ((xu va) or (tu va)) dao va cua tre*.