, some volumes and fragments can be viewed or downloaded legally through archives and educational platforms: Internet Archive
The series (which includes the original 18-volume collection and the more recent "Nuevos Enigmas") addresses questions such as:
If you search hard enough, you will likely find a Ariel Alvarez Valdes Enigmas de la Biblia PDF floating around in a Telegram channel. However, for the integrity of your study and to support Christian scholarship,
The work by Argentine biblicist Ariel Álvarez Valdés