I am not sure I follow your description fully - it seems that your field "PublicationID#" is also used to record the publication's title, and that its type is Number.
You should use two separate fields in the Publications table:
• PublicationID - Number, Auto-enter serial number
• Title - Text, Unique
The relationship to Adverts should use the PublicationID field only. This way you can change the publication's title without breaking the links to Adverts.