Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
sach ky » sac ky, sach y, sach ty
ve cham » va cham, ve chat, vu cham
va hanh » van hanh, va thanh, va danh
ve cac » va cac, vien cac
cua te » cua tu
x hoi » xa hoi, o hoi, x ho
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky nang x hoi. hieu ((ve cham) or (ve cac)) duc va hanh vi ((cua te) or (va thiet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky nang x hoi. hieu ((ve cham) OR (ve cac)) duc va hanh vi ((cua te) OR (va thiet)).
• Adding a wildcard symbol may retrieve word variants: doc sach ky nang x hoi. hieu ((ve cham) or (ve cac)) duc va hanh vi ((cua te) or (va thiet))*.