$ pbzip2 -dc /public/dumps/public/enwiki/20210220/enwiki-20210220-pages-articles-multistream.xml.bz2 | grep pmc | grep -Eo "(url= *http[^}]+pmc *= *[0-9]|pmc *= *[0-9][^}]+url= *http)" | grep -Eo "url= *http[^|]+" | cut -f3 -d/ |sort| uniq -c | sort -nr| head -n 50
   1181 www.ncbi.nlm.nih.gov
    915 pubmed.ncbi.nlm.nih.gov
    840 www.pnas.org
    621 www.nature.com
    492 journals.plos.org
    465 doi.org
    407 zookeys.pensoft.net
    353 academic.oup.com
    299 www.cell.com
    299 www.bmj.com
    285 dx.doi.org
    268 www.sciencedirect.com
    179 www.thelancet.com
    174 www.parasite-journal.org
    166 www.genetics.org
    166 onlinelibrary.wiley.com
    155 royalsocietypublishing.org
    151 www.plosone.org
    145 www.mdpi.com
    127 www.pensoft.net
    123 dx.plos.org
    111 www.biomedcentral.com
    111 web.archive.org
    109 link.springer.com
    101 www.frontiersin.org
    100 books.google.com
     97 nar.oxfordjournals.org
     93 peerj.com
     85 linkinghub.elsevier.com
     84 www.cdc.gov
     83 aem.asm.org
     72 doi.wiley.com
     72 advances.sciencemag.org
     71 europepmc.org
     67 wwwnc.cdc.gov
     63 www.cmaj.ca
     59 jb.asm.org
     58 www.who.int
     58 www.researchgate.net
     56 journals.sagepub.com
     51 jvi.asm.org
     50 ajph.aphapublications.org
     49 www.plantphysiol.org
     49 bmjopen.bmj.com
     48 aob.oxfordjournals.org
     47 www.jbc.org
     46 archive.org
     45 www.cambridge.org
     45 science.sciencemag.org
     42 jnnp.bmj.com