A Mixed Media Reality (MMR) system and associated techniques are disclosed. The MMR system provides mechanisms for forming a mixed media document that includes media of at least two types (e.g., printed paper as a first medium and digital content and/or web link as a second medium). In one particular embodiment, the MMR system provides a method to associate related documents. The method acquires two associated documents and associates the related portions together. When the method acquires a portion of one of the document, it identifies the portion acquired, and provides the related portion of the other document.