It's one of my favorite papers on CRDTs and provides practical pseudocode for learning how to implement CRDTs yourself.
The structures they present are simple to understand and have good performance characteristics compared to similar CRDTs .
A key insight from the second paper is to write CRDTs that optimize for applying remote operations over applying local operations, as the ratio of remote operations to local operations will be greater. i.e. 100 clients making 1 change to a CRDT will require all 100 clients to each apply 99 remote operations and 1 local operation.
 Replicated abstract data types: Building blocks for collaborative applications - http://dl.acm.org/citation.cfm?id=1931272
 Evaluating CRDTs for Real-time Document Editing - http://hal.archives-ouvertes.fr/docs/00/62/95/03/PDF/doce63-...
Thanks for the other pointers, though!