To find a clear, high-resolution copy, you can utilize the following academic and document-sharing platforms: Academia.edu
The book is still under copyright in most countries (life of author + 70 years; Santaló died in 2001 → copyright until at least 2071). There is no legal free PDF distributed by the publisher (EUDEBA has gone through changes; some rights now belong to Editorial Universitaria de Buenos Aires or the Santaló estate). geometria proyectiva santalo pdf dow high quality