Exhibition ephemera and catalogues, notably from the 1960s to 70s, collected by Ha form a part of his archival practice. Many of these materials were organised and placed in dedicated boxes. Digitisation of the catalogues and ephemera is prioritised according to their rarity and physical condition. The digitized images, which include photo documentation, exhibition ephemera, clippings, correspondence, and manuscripts, are then categorised according to the boxes in which they were placed at Ha’s studio.