Title: 3-way match (GR-IV mismatch issue resolution using SAP) as analysis method for a list of multiple PO & Billing documents with discrepancies | by Kuo Sheng Ang | Medium
SAP ABAP Table RBVDMAT (Invoice Verification - Aggregation Data, Material), sap-tables.org - The Best Online document for SAP ABAP Tables
Enhancing The Field Catalog of Condition Tables For Output Billing Documents | SAP Blogs
SAP Document Flow - Understanding the basics with examples