https://www.thevespiary.org/rhodium/Rhodium/chemistry/vogel3.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/vogel3.html)
http://www.chem.ucalgary.ca/courses/351/Carey5th/Carey.html (http://www.chem.ucalgary.ca/courses/351/Carey5th/Carey.html)
http://www.cem.msu.edu/~reusch/VirtualText/intro1.htm#contnt (http://www.cem.msu.edu/~reusch/VirtualText/intro1.htm#contnt)