Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nang xa » nang x, lang xa, nang ma
va cam » va cham, va cac, va cai
y nang » ky nang, ly nang, v nang
va dan » ca dan, va dao, va dau
tu cau » tu cac, cu cau, tu can
tu cua » hu cua, vu cua
va cao » va cac, va co, va dao

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 xa hoi. hieu ((va cam) or (va cao)) duc va dan ((tu cau) or (tu cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang xa hoi. hieu ((va cam) OR (va cao)) duc va dan ((tu cau) OR (tu cua)) tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y nang xa hoi. hieu ((va cam) or (va cao)) duc va dan ((tu cau) or (tu cua)) tre*.