Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nuoc van » nuoc va, nuoc san, luoc van
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
hieu van » thien van, lieu va, hieu ve
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
cao hoc » co hoc, cho hoc, chat hoc
vai cua » dai cua, hai cua, lai cua
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
co hoi » co hoc, co loi
cua su » qua su

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky nang ((cao hoc) or (co hoi)). ((hieu va) or (hieu van)) cac nuoc van hanh vai cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang ((cao hoc) OR (co hoi)). ((hieu va) OR (hieu van)) cac nuoc van hanh vai cua su.
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang ((cao hoc) or (co hoi)). ((hieu va) or (hieu van)) cac nuoc van hanh vai cua su*.