It is a sad fact that the reference systems for Tipitaka - especially for the Anguttara and Samyutta Nikayas - is a chaos. There are several different systems in use, and finding a given text in the Anguttara and Samyutta can be quite difficult at times, especially if the reference given does not match the reference system in the edition you are looking into.
The only really consistent system that I know, is the one that is used in the Bangkok edition of the Tipitaka, where any part of any text can be easily located by reference to volume, page and paragraph. But no one else is using this system.
It would be a very good thing if an international committee could decide on a clear, consistent and universal reference system for the entire Tipitaka - and every publisher of texts and translations then could use that system. But I fear that different editions already are so deep entrenched in the systems they already use, that this is not very likely to happen.