CBIRDS uses Collections to holds Works together. In most cases a collection is a series/serial and will holds multiple Works together. But also a single work belongs to a Collection.
The collection includes all properties that are applicable to each of the comprising works such as the Main Title. This structure eliminates data redundancy and guarantees referential integrity between collections and works. Both collections and works can hold unique identifiers of different organizations such as other CMO's but also EIDR, ISAN and IDA.