Using Spanish to Boost Google Placement

I really like putting up blogs with blogger and have been experimenting with adding spanish subtitles. I've noticed it gets me up higher in google search. Here's an example, my Civil Rights Books blog -- MOVIMIENTO DE DERECHOS CIVILES LIBROS...

Civil Rights Books

When I searched google for civil rights books, this blog came up in seventh position. And when I google MOVIMIENTO DE DERECHOS CIVILES LIBROS it comes up first!!