** [https://standards.cen.eu/dyn/www/f?p=204:22:0::::FSP_ORG_ID,FSP_LANG_ID:1883209,25&cs=126F1BDBC8D6D6141F550EB578B4A9CF4 standardointityön aikataulut]
* [https://twitter.com/search?f=tweets&vertical=default&q=%23TC434&src=typd twitter.com #TC434]
* [https://twitter.com/search?f=tweets&vertical=default&q=%23eInvoicing&src=typd twitter.com #eInvoicing]
* [http://www.cen.eu/work/areas/ict/ebusiness/pages/einvoicing.aspx cen.eu - eInvoicing] sähköisen laskutuksen workshop tulokset