v2
cat Bibliography.rtf | sed 's/doi.org//
/g' | grep "^[0-9]" | sed -r "s/.{2}$//" > new.txt
v1
cat Bib.rtf | sed -e 's/doi:/'$'
/g' | grep "^[0-9]" | sed -r "s/.{3}$//" > new.txt
^ add new lines ^begin with numbers ^remove last 3 characters
bib.rtf file was created using zotero 6.
select all > right click > create Bibgraphy > export rft