The reason many search for the version is the density of information. The manual typically includes:
[PDF] 100 Circuitos con el 555 de Newton C. Braga () - Perlego download 100circuitosconel555pdf 5 mb hot
No full version of 100 Circuitos con el 555 is legally free. However, similar books from the 1970s–80s have entered the public domain in some countries. Check the (archive.org) for “555 timer circuits” – several out-of-copyright books are available for legal download. The reason many search for the version is