Hi. I'm currently writing a study on life of Olga of Kiev. Part of it should consist of icongraphy. I have a chronicle of John Skylitzes on my hand but to contrast I would also like to include the Radziwiłł letopis. Unfortunately I have not been successful in finding one neither online nor in paper. If anyone could point me towards an online source that would be great. Thanks.
I had the same problem like a year ago, and I couldn't find it translated to English anywhere online, but I did find a scan of the text so I figured it might be of some use to you, especially since you mentioned iconography.
https://archive.org/details/radziwill-chronicle/mode/2up
I can also send you a pdf of the text in Russian (in a few hours, I'm not home) if you happen to speak the language.
u/ylmz4 found what you were searching for, but if you seek additional sources, here is a link to an online version of the Kyivan Psalter attributed to Spiridon of Kyiv, on the website of the Russian Presidential Library. It has lots of lovely illustrations, like the Radziwiłł litopys.
If you require more textual sources, on izbornyk you can find text versions of many different textual variations of the litopysy, such as the Hypatian and Lavrentian. Some texts must have been transcribed before Unicode supported all the archaic Cyrillic letters, because the transcribers at izbornyk.org.ua consistently wrote «Ђ» instead of «Ѣ» in texts such as the Hypatian pověstʹ vremennykh lět. Nevertheless, izbornyk is a phenomenal resource.
In addition, if your library can acquire a copy of The pověstʹ vremennykh lět: an interlinear collation and paradosis compiled by Donald G. Ostrowski, Horace G. Lunt, and David J. Birnbaum, then I would highly recommend utilizing it in your research. The editors listed all variants of the pověstʹ line by line, allowing one to instantly observe the textual differences between the different manuscripts. Alas, I don't know of any scanned copies available on the Internet, but if your library can purchase or borrow it, take advantage of the opportunity. I will list the bibliographical information at the end of this comment.
I wish you good luck on your project!
Ostrowski, Donald G., Horace G. Lunt, and David J. Birnbaum, eds. The pověstʹ vremennykh lět: an interlinear collation and paradosis. 3 volumes. Harvard Library of Early Ukrainian Literature: Texts 10. Cambridge: Harvard University Press, 2003. ISBN 9780916458911.