http://www.toratemetfreeware.com/online/f_01961.html
https://beta.hebrewbooks.org/pagefeed/hebrewbooks_org_26470_86.pdf
http://www.toratemetfreeware.com/online/f_01961.html#HtmpReportNum0...
http://shturem.net/index.php?section=artdays&id=3055
https://www.avotaynu.com/Kwadrat.pdf
https://upload.wikimedia.org/wikipedia/commons/4/4f/%D7%A1%D7%A4%D7...
https://books.google.com/books?id=oFY4AAAAYAAJ&pg=RA1-PA28&...
https://books.google.com/books?id=-mRBAAAAYAAJ&pg=PR48&lpg=...
https://books.google.com/books?id=PyxNAQAAMAAJ&pg=PA43&lpg=...