Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
hieu van » hieu va, thien van, lieu va
dua tren » dung tren
hanh hu » hanh khu, hanh nhu, hanh tu
va hanh » van hanh, va thanh, va danh
cac tuc » cac toc, cac tu, cac tac
van cac » van hac, van cau, van bac
sach ky » sac ky, sach y, sach ty
tuc va » thuc va, truc va, tuc xa
cua te » cua tu
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: thuat sach ky nang ((x hoi) or (o hoi)). hieu van cac tuc va hanh hu ((dua tren) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((x hoi) OR (o hoi)). hieu van cac tuc va hanh hu ((dua tren) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: thuat sach ky nang ((x hoi) or (o hoi)). hieu van cac tuc va hanh hu ((dua tren) or (cua te))*.