I need a sole source document. Where can I find it? December 10, 2020 13:50 Updated You can download a PDF of our sole source letter: Sole source letter (PDF) Related articles I need a copy of your W-9. Where can I find it? What is the difference between Intervention levels and Reading Recovery levels? Can I write to Bella and Rosie? Do you use outside illustrators? How do you determine shipping rates?