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