# Additional resources

Source: https://developer.avalara.com/products/e-invoicing/integration-guides/elr/elr-resources/

Guide: E-Invoicing and Live Reporting

# Additional resources

The following additional resources can be helpful to you when completing the milestones described in this guide:

-   [Avalara E-Invoicing eBook](https://www.avalara.com/eu/en/learn/whitepapers/the-future-of-e-invoicing.html)
-   [Avalara E-Invoicing API](https://developer.avalara.com/api-reference/e-invoicing/v1.6)
-   [UBL 2.1 - Documentation](https://docs.oasis-open.org/ubl/os-UBL-2.1/UBL-2.1.html)
-   [Peppol BIS Billing 3.0 - Invoice Schema](https://docs.peppol.eu/poacc/billing/3.0/syntax/ubl-invoice/tree/)
-   [E-Invoicing FAQ](https://ec.europa.eu/digital-building-blocks/wikis/display/DIGITAL/eInvoicing+FAQ)