One of the known two manuscripts of the Book of Dede Korkut, that has recognized as one of the masterpieces of Turkish literature and has been used as one of source books of Turkish language, literature, art, and history, was discovered in the Royal Library of Dresden, Germany, in 1815. The second manuscript was discovered in Vatican Library in 1952. The manuscript preserved in Dresden consists of an introduction and twelve epic stories, and the manuscript preserved in Vatican includes an introduction and six epic stories. Since the discovery of the first manuscript and introduced to the scholarly world by H. F. von Diez in 1815, there has been number of research and publications on linguistic, literary, folkloric, art and cultural historical aspects of the book. There have many more research and publications expected to be come. On the one hand those scholarly works have been carried on, on the other hand the answers to, the questions of when, where and why the unknown scripts and authors was wrote down those manuscript; whether they had collected from oral sources or copied from another book, and also are there more epic stories about the Oghuz heroes attributed to Dede Korkut have been discussed. One of the reasons rising for those questions is that frequent use of epithets while introducing a hero in any of the epic stories. Some scholars believe in that some of the epithets are the signal of some other epic stories. One of Oghuz heroes who is the main figure of three epic stories is Salur Kazan who is introduced with number of epithets. Salur Kazan, who is introduced in the Book of Dede Korkut as the son-in-law and the minister of the Bayindir Khan who is recognized as the khan of khans, has the most important place after Baymdir Khan. In the epic stories in two manuscripts he has been introduced as "the son Ulas, the young of feathering bird, the hope of poor, the lion of Amit stream, the tiger of Karacuk Mountain, the owner of the chestnut-brown horse, the father of khan Uruz, the son-in-law of Khan Bayindir, the pride of crowded strong Oghuz people, the support of young warriors in distress Salur Kazan ..." (Gokyay 2006: 39). As understood from these epithets, Salur Kazan Khan has a very important place within the Oghuz nobles, and is important figure among Oghuz heroes. Although a little information provided about the Bayindir Khan in the manuscripts, Salur Kazan Khan appears as the main heroic figure of three epic stories. He is also mentioned some other epic stories. It has been a question and long has been discussed among the epic scholars whether those epithets of Salur Kazan are the messenger of some other epic stories related about him and other noble Oghuz heroes. In this article, first I would like to provide information on the third manuscript of Dede Korkut, which was discovered by Yahya Vali Mehemmed Hoca who lives in the city of Gumbet-i Kavus located in Turkmen-Sahra region of Iran. The manuscript was sent to me via internet in Pdf format that I named as "Turkistan/Turmensahra" manuscript of the Book of Dede Korkut. The second, I would like to share the contemporary Turkish translation of "The Story of Salur Kazan Kills the Seven Headed Dragon" by epic scholars for the first time. It has to be noted that with addition of "The Story of Salur Kazan Kills the Seven Headed Dragon" the number epic stories of Dede Korkut reaches to thirteen, and as a result of this new addition this epic story should be recognized as the thirteen epic story related to Dede Korkut.