You can find digitized volumes of the Enciclopedia Hispánica (Barsa Planeta) on the Internet Archive , which allows for borrowing or browsing specific volumes in PDF-like formats.
"Barsa" is a portmanteau of the surnames of William Bar low and his wife Alice Sa nders. enciclopedia barsa pdf
While the official publishers focused on digital platforms, many legacy editions have been digitized into PDF format You can find digitized volumes of the Enciclopedia