Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu cao » chieu cao, hieu ca, kieu cao
danh dai » danh dau, danh di, danh sai
vat danh » va danh, van danh, luat danh
cap thuc » can thuc, cay thuc, tap thuc
hieu cac » hieu luc, hieu va, hieu van
cau tren » cu tren, dau tren, ca tren
sach ty » sach y, sach tu, sach thu
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 cac)) cap thuc vat 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 cac)) cap thuc vat 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 cac)) cap thuc vat danh dai cau tren*.