We describe an electronic document reader system for viewing electronic documents, in which the electronic documents are viewable on a removable electronic document reader display that is useable whilst removed from an electronic document reader display holder. The system comprises: a removable non-volatile display for viewing electronic documents thereon, the display having a display portion on which electronic documents are viewable; a display holder for receiving the removable display, the display holder comprising a back, and an open front shaped to receive the removable display, each of the display and the holder having an electrical interface, wherein, when the removable display is received in the open front, the removable display and holder form an electrically connected combined unit to enable the display to receive document data from the holder for display, and wherein the removable display is useable to read electronic documents when removed from the display holder.