Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
danh dai » danh dau, danh di, danh sai
cap truc » cau truc, tap trac, tap tuc
hieu van » hieu va, thien van, lieu va
hieu cao » chieu cao, hieu cac, hieu ca
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, sach thu
truc va » thuc va, thuc vat, trung va
va danh » va dinh, va dan, va hanh
ty nang » ky nang, ty xang, ty hang
dai cau » dat cau, da cau, dai hau
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

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 ty nang ((x hoi) or (o hoi)). ((hieu cao) or (hieu van)) cap truc va danh dai cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty nang ((x hoi) OR (o hoi)). ((hieu cao) OR (hieu van)) cap truc va danh dai cau tren.
• Adding a wildcard symbol may retrieve word variants: thu sach ty nang ((x hoi) or (o hoi)). ((hieu cao) or (hieu van)) cap truc va danh dai cau tren*.