These are the errors encountered while trying to harvest the PDF files listed in the URL column of the Zotero spreadsheet.
http://search.proquest.com/openview/4c783b1604b9cd99be75746aba3d46a8/1.pdf Server redirected too many times (20) http://www.lbd.dcc.ufmg.br/colecoes/escience/2016/007.pdf connect timed out
IWSG2017_paper_18.pdf
http://www.assamsciencesociety.org/assjournal/Vol-56-No-2-01.pdf https://pdfs.semanticscholar.org/b056/c9c5deda9ce754a3d4bf9b45fc46e40ddc9e.pdf https://clerisyonlinepublishers.org/articles/JBRCCR/Bioinformatics-Tools.pdf https://marybethkery.com/projects/Verdant/Towards_effective_foraging_by_data_scientists.pdf http://thejaps.org.pk/docs/Accepted/2019/29-02/16.pdf https://lib.ugent.be/fulltxt/RUG01/002/782/856/RUG01-002782856_2019_0001_AC.pdf https://www.sage-care.eu/wp-content/uploads/2019/07/Masterthesis_MarkusLeipold.pdf
https://www.currentscience.ac.in/Volumes/118/07/1042.pdf PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target https://libres.uncg.edu/ir/asu/f/French_Patrick_Spring%202020_Thesis.pdf PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested targetxq