Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
te sach » toc sach
vai cuu » vai cua
dan vai » dan va, dan tai, dan vat
cao duc » dao duc, cao suc, giao duc
cam duc » cam xuc, pham duc, nam duoc
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
cuu tre » cua tre, cau tren, cau treo
va dan » ca dan, va dao, va dau

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 ((ky lang) or (ky dang)) xa hoi. hieu van ((cam duc) OR (cao duc)) va dan vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky dang)) xa hoi. hieu van ((cam duc) OR (cao duc)) va dan vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) or (ky dang)) xa hoi. hieu van ((cam duc) OR (cao duc)) va dan vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) or (ky dang)) xa hoi. hieu van ((cam duc) OR (cao duc)) va dan vai cuu tre*.