Bibliotheeca Scriptorum Graecorum et Romanorum Teubneriana, Eutropii Breviarium Ab Urbe Condita, recognovit Carolus Santini. It's the 2011 reprint of the 1992 of the 1979 edition.
The thing is, it's very wide and tall compared to earlier editions from Teubner's renowned Library. Aside from the Library, Teubner would publish a critical edition now and then in quatro, but the Library's volumes, from the beginning in the mid-19th century on, were small octavios, about 4 1/2 by 6 inches. They fit into many pockets, these old Teubners. Then, around the 1960's or 70's, perhaps, they suddenly grew to about 5" by 7", and in the 1990's some new editions were just barely larger than that, and now there's this Eutropius -- and, I assume, other recent titles: 6.1" by 9.1". That's not going to fit into any pocket of anyone I know. With small purses it'll be between dicey and impossible. Backpacks are needed.
Does this bother me? Yeah, kinda. I'm used to sticking the old, pre-1960's Teubners into a jacket pocket. I'll live.
A surprising detail on this 2011 reprint -- and other recent titles -- is that, apparently, De Gruyter has taken over the operation from K G Saur. In the past 2-3 years, I'd guess. La-dee-da, eh? In addition to growing the volumes to an unwieldy size, De Gruyter has given the covers a new design.
Since before 1900, a blue cover on a Teubner Library volume meant the text was Latin, and an orange or red cover meant it was Greek. And it mostly still does, but: now there's also at least one green cover, on: Papyri Graecae magicae. Die griechischen Zauberpapyri: Vol. I. Greek papyrii used to be in orange covers like other Greek material. Does the green signify papyrii? or perhaps that some of the apparatus is in German? Or perhaps something else? Beats me. And a couple of volumes look more yellow than orange or red to me. Chaos. Chaos and decadence, and change is bad. Unwieldy sizes and unnecessary proliferation of colors of titles, and apparatus in vernaculars. 2 books of Livy per volume. As recently as a couple of decades ago every Teubner volume of Livy contained 5 books. And sometimes a little more: the Mueller/Weissenborn edition, printed until the mid-20th century, also included the periochae and testimony of the missing books. Yr dang right that was cool. Use to be before that, before Teubner, centuries ago, 1 volume would more often than not have all 35 books. You call this a martini?! This is no way to run a railroad! Get off my lawn, you punks! *shaking my fist at a cloud* Seriously, though, it's bad.
And even more in earnest: even with all the decadence, Teubner still kicks the living shit out of the Oxford Classical Texts and every other publisher of ancient Classical texts I know. Here and there an individual volume by Oxford or even by (shudder, facing-page translation, decadence, decadence) Loeb may be the one you want, or one by Brill or Bude or someone else. But all things being equal, always check Teubner first, it saves time. Teubner is the big leagues. Teubner is the quality shizznit. It's the stuff. Still.
The index historicus of the 1979/1992/2011 Santini Eutropius, in addition to giving the location in the volume itself of its subjects, also refers in many cases to der kleine Pauly (dkP), and in a few other either to The Prosopography of the Later Roman Empire (PLRE) or to the Pauly-Wissowa (PW).