A preprint, just arrived on SocArxiv: “Digital blackout of Spanish scientific production in Google Scholar”…

“An abrupt drop in the number of Spanish scientific journals covered in [since] the last edition of Google Scholar Metrics (2012-2016) has been detected. […] After considering several hypothesis to explain this phenomenon, we conclude that the main cause was the sudden disappearance of the Spanish bibliographic database Dialnet from Google Scholar.”

I’d add that parts of Ex Libris also summarily removed Dialnet in July 2017…

“all titles will be removed from Dialnet database in the Knowledgebase on July 20, 2017. The database will become a zero-titles database.”

This might suggest that the Google Scholar cut-out — apparently of some 2m Dialnet items — was just ‘an up-stream -> down-steam thing’ that flowed into Google Scholar. Due to the way they have their automated inputs set up from their partners? Just my guess.