Bulgaria Unknown Document, Translation help please!

[Stogieman]

I picked up a small MVR group, mostly jubilee medals, similar to much already seen/posted. However, there is this one document in the group I have not seen before. Can anyone help to explain what this is?

Thanks! Rick

[Stogieman]

Interior:

[Theodor]

Cover: Regional Direction of MVR, Varna To comrade Yordan Dimitrov Andreev

Inside left: "We are highly confident that the victoriously marching socialist revolution in Bulgaria will never be hit in the back out of the blue, because our rear is strongly and reliably armored by people, for which as the poet says, "there are no armor-piercing bullets invented"" Todor Jivkov

Inside right: The official and the party leadership of the Regional direction of MVR - Varna is greeting you on the occasion of 40 years of the victory of the Socialist revolution and the creation of the organs of MVR. FROM THE LEADERSHIP

No mention of a badge or medal, so this could be just a greeting card? Of course, may have come with a badge, too?

[Stogieman]

Hi Theoodor, Thanks! He received a forty years revolution medal, but not a 40 years MVR. Well, at least not with group if he did get it. There is a 20, 25, 30 year jubilee medal. My speculation is maybe he was retired already? Still interesting and first time I have seen a card like it. Thanks!