https://ttlc.intuit.com/questions/3884861-i-also-received-the-ftb-3904-asking-to-confirm-if-i-filed-my-taxes-i-signed-it-and-faxed-it-back-does-anyone-know-how-long-it-will-take-to-get-my-refund
https://www.ftb.ca.gov/Archive/Professionals/Taxnews/2014/December/04.shtml
https://ttlc.intuit.com/questions/3360109
https://www.caltax.com/news/hot-news-and-notes/the-ftb-is-sending-requests-to-confirm-tax-return-filing
https://www.caltax.com/news/hot-news-and-notes/the-ftb-is-sending-requests-to-confirm-tax-return-filing