http://www.arkat.org/arkat/journal/Issue6/ms03-0081.pdf (http://www.arkat.org/arkat/journal/Issue6/ms03-0081.pdf)
https://www.thevespiary.org/rhodium/Rhodium/chemistry/dialkoxybenzaldehydes.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/dialkoxybenzaldehydes.html)