The concept of publishing the Simeon Collection – an Old Bulgarian translation from the late 9th – early 10th century – in three volumes, each with a separate purpose, under the general editorship of Academician Petar Dinekov, is one of the initiatives of the Cyril and Methodius Scientific Center at the Bulgarian Academy of Sciences and the Language and Textological Laboratory at Sofia University “St. Kliment Ohridski” headed by Prof. Dr. Philology Rumyana Pavlova. The first volume, containing research, text and bibliography, was published in 1991, and the second – a dictionary-index of word forms and word usages in the Svetoslav transcript of 1073 – in 1993. The typescript was prepared based on the earliest transcript of the Simeon Collection – the Russian Svetoslav transcript of 1073 according to the phototype edition of 1983 (Moscow). The proposed third volume is dedicated to the Greek sources of the Old Bulgarian translation. It includes a critical edition of the Greek text based on four Byzantine copies of Greek collections (the manuscripts Coislinianus graecus 120, Coislinianus graecus 258, Vaticanus graecus 423 and Ambrosianus graecus 489, olim L 88 sup.), which are closest to the Slavic collection, and a theoretical part – a study of these Greek manuscripts, which can be defined as its analogs. Both the study and the edition of the Greek sources of Simeon’s collection are the result of Petya Yaneva’s long-term work on the Greek text of the anthology. In order to facilitate the future work of researchers of the Slavic translation as much as possible, the typescript edition of the first volume, reviewed and further verified by Angelina Mincheva, Tsvetana Raleva, Tsenka Doseva and Petya Yaneva, is given in parallel with the Greek text, with the Greek parallels being synchronized with the Slavic translation according to the Svetoslav transcript of 1073. The publication of the Greek sources of Simeon's collection, which concludes the three-volume edition "Simeon's Collection (according to the Svetoslav transcript of 1073)", is a remarkable achievement of Bulgarian medieval studies.