Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va triet » va thiet, va trien, ve triet
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
va cam » va cham, va cac, va cao
ve cac » va cac, vien cac
cua tu » cua tuc, cua su, cua cu
x hoi » xa hoi, o hoi, x ho

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 y nang x hoi. hieu ((va cam) or (ve cac)) duc va hanh vi ((cua tu) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang x hoi. hieu ((va cam) OR (ve cac)) duc va hanh vi ((cua tu) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: toc sach y nang x hoi. hieu ((va cam) or (ve cac)) duc va hanh vi ((cua tu) or (va triet))*.