The folksong heard by Ulrich and Boris on pages 61–2 is adapted from a song described by Tim Rice in his account of Bulgarian music, May It Fill Your Soul (University of Chicago Press, 1994), page 154.
The opening of Alexander Pushkin’s Eugene Onegin on pages 121–2 is adapted from a translation by Vladimir Nabokov (Princeton University Press, 1991, page viii) and the translation by James E. Falen (Oxford World’s Classics, 1998, page 5).
The jokes on pages 122–3 are adapted from Russia Dies Laughing: Jokes from Soviet Russia by Zhanna Dolgopolova (Unwin, 1983).
The lines on page 223 are from Anna Akhmatova’s poem ‘Requiem’ as translated by Judith Hemschmeyer in Selected Poems of Anna Akhmatova (Zephyr Press, 2000).
The extract from Plato’s Symposium on page 329 is adapted from the translation by Christopher Gill (Penguin Classics, 2003) and the translation by Benjamin Jowett (Dover Thrift, 1994).
Irakli’s poem, ‘The dream of the embryo on the night before birth’, on page 335, is adapted from Eliot Weinberger’s translation of ‘Nocturno Preso’ by Xavier Villaurrutia in Nostalgia for Death (Copper Canyon Press, 1993), page 23.
For information on Einstein’s life I was particularly indebted to Das Verschmahte Genie: Albert Einstein und die Schweiz by Alexis Schwarzenbach (Deutsche Verlags-Anstalt, 2005).