Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cham duc » pham duc, cham soc, pham duy
hieu va » lieu va, hieu qua
van anh » van thanh, tuan anh, van minh
duc van » duc va, duc tan, duc manh
ca tren » cau tren, cu tren, la tren
hieu ve » hieu van
nang xa » nang x, lang xa, nang ma
anh va » hanh va
va ca » va cac, va cao, va cai

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) OR (toc sach)) ky nang xa hoi. ((hieu ve) or (hieu va)) cham duc van anh va ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang xa hoi. ((hieu ve) OR (hieu va)) cham duc van anh va ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang xa hoi. ((hieu ve) or (hieu va)) cham duc van anh va ca tren".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang xa hoi. ((hieu ve) or (hieu va)) cham duc van anh va ca tren*.