Hello,

Currently, the publisher of the Absolute Duo light novels, Media Factory, has not developed an official version copy in English. Usually, the franchise needs to become popular enough domestically before a publisher deems it profitable enough to translate it, making a gamble for the international market.

Until then, you can always do three things:

• Read a translated light novel, such as one by Baka Tsuki;
• Read a translate manga; or
• Watch the fan-subbed anime.

Now, while I can't endorse it, the official light novel can be found here. (mediafactory.jp).

Hope you keep on keeping on!