In Greece, it’s not particularly difficult to find all the works of Kazantzakis in any middling bookstore; and bless you for mentioning the Terza Rimas, that I have a lot of affection for.
In the Anglosphere, a university with a Modern Greek teaching program will have them. A university that used to have a Modern Greek teaching program, like the University of Melbourne, will have banished them to storage.
From Nikos Kazantzakis – Wikipedia, I see a lot of translations of the more obscure works have appeared in very obscure places—literary journals in the 1970s, limited edition runs of 140. Neither Julian nor the Terza Rimas have been translated, although the Terza Rima I use as one of my email .sigs has been:
- Christ (poetry), translated by Kimon Friar, “Journal of Hellenic Diaspora” (JHD) 10, No. 4 (Winter 1983), pp. 47–51 (60).
You can download that issue at: Issues 1-2, 3, 4