http://www.chemikalienlexikon.de/aroinfo/0568-sy2.htm (http://www.chemikalienlexikon.de/aroinfo/0568-sy2.htm)
https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.html#methylenation (https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.html#methylenation)
https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.bonthrone-cornforth.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/methylenation.bonthrone-cornforth.html)