FreePDF: The functions for working with Article strings are not included in FreePDF.
You can add new article boxes to an existing article thread as follows:
| 1. | Open the page containing the article box to which you want to assign a new follow-up box. |
| 2. | Enable the Article tool  on the ribbon tab Insert | group Articles. |
| 3. | Click on the article box (let's call this box A) that is to precede the new article box. |
| Tip: The article box is only selected correctly if the blue handles appear at the corners. |
| 4. | Click on the + icon at the bottom right of box A. |
| 5. | Drag your new article box with the mouse. This will now be inserted in the article thread as the follow-up box of box A. |