Codices Hugeniani Online (COHU) offers the fully digitized archive of Christiaan Huygens (1629 - 1695), held at Leiden University Library. The archive includes notebooks and loose leafs with texts in the field of astronomy, mechanics, mathematics and music, as well as correspondence and annotated books.

This collection of archival documents contains material that describes the history of Soviet culture and theater, Jewish avant-garde art and the Kremlin’s policy toward Jewish society and culture from 1919 until 1949. Among the artists associated with GOSET are Marc Chagall, Natan Al’tman, Isaac Rabinovich, Robert Falk, Aleksandr Tyshler, and others. The collection contains correspondence with ministries, state organizations, and authors; administrative-managerial documents; plays performed by or submitted to the theater (many of which have never been published); notes written by the censors; musical items for productions; press clippings about the theater; posters, programs and librettos; photographs of GOSET productions and of the actors off -stage; as well as personal documents of Alekseĭ Granovskiĭ, Solomon Mikhoėls, V.M. Zuskin and other members of the troupe.

This edition presents a broad cross-section of the Wagner literature of the nineteenth century as held by the Zentralbibliothek Zürich, which possesses one of the world’s finest collections of Wagneriana. The collection consists of three parts:

- Secondary Literature of the Nineteenth century (129 titles)

- Wagner’s Mein Leben, 1870-1880

- Mathilde Wesendonck `s Complete Published Writings (15 titles)