Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cay tren » chay tren, ca tren, cau tren
hieu ve » hieu va
nang co » nang cao, nang doc, nang noi
cam tuc » cam tu, nam thuc, dam thuc
dan cua » dan ca, ban cua, dai cua
cua cay » cua cac
co hoi » co hoc, co loi
y nang » ky nang, ly nang, v nang
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: thu sach y nang co hoi. ((hieu ve) or (hieu van)) ((cam tuc) OR (cam xuc)) va dan cua cay tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang co hoi. ((hieu ve) OR (hieu van)) ((cam tuc) OR (cam xuc)) va dan cua cay tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang co hoi. ((hieu ve) or (hieu van)) ((cam tuc) OR (cam xuc)) va dan cua cay tren".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang co hoi. ((hieu ve) or (hieu van)) ((cam tuc) OR (cam xuc)) va dan cua cay tren*.