Dr. Gancho Tsenov (* 1870 – † 1949) was a Bulgarian historian. He founded the autochthonous theory of the origin of the Bulgarian people, which hw detailed in 1910 in his main work, The Origins of Bulgarians and the Origin of the Bulgarian State and the Bulgarian Church.
- "The Turkish and Greek tyrants had reduced the Bulgarian people to the lowest level of human culture, but their Bulgarians could not be rooted out. Under the consciousness of the people, there were still embryos of national sense. The Bulgarian people realized that it was a people and had its own independent state, and it even managed to win its people's church. Russia freed part of the Bulgarian people. The liberated Bulgarians were called for autonomous rule, but they were divided into two factions.... One of them, the Slavophiles, thought that Bulgaria should be placed under Russia's protectorate because it could rule itself.... The other faction, the Patriots, wanted an independent Bulgaria. The fierce struggles between both factions filled the history of Bulgaria from its independece to the world war. Russophiles grew up with various modern trends, such as communists, socialists, and other truths that did not give birth to tobacco and native tobacco. The fatherland was considered a vice for backwardness. It is hard to say that one is a patriot."
- "In the time of his reign (Anastasius), the Thracian Vitalian kept under some pretense by using of the exiled bishops, and he took Thrace, Scythia and Moesia, to Varna and Anhialo and led a large number of Huns and Bulgars." 
- "When I published my book "The Origins of the Bulgarians" in 1907, from which it came out that the Bulgarians were something better than what was being thought of for them, I was declared a patriot and therefore outside the law. Everyone who criticized me criticized me not in content or because the datavl that I stated is untrue, but because I was a patriot who reported the facts that the Bulgarians were both valiant and cultural when in the opinion of my opponents, it was obvious that the Bulgarians were created by nature as a fertilizer on foreign fields.... My chauvinism, proving that Thrace and Macedonia were old Bulgarian lands, threatened on the one hand Russia, which aspired to South Thrace as a hinterland of the Dardanelles and on the other hand, the Pannonian Slavs, who aspired to Thessaloniki. The opinion of Paninese Slavs was also supported by Bulgarian scientists. 
- Tsenov comes out of a detailed source-check, which many of his predecessors have hardly ever seen. It facilitates the reader by printing these sources in the original.... From the same sources, it can be seen that the Bulgarians were south of the Danube for 350 years and so they did not come until 679 from the Volga before the Slavs and also before the Huns in Illyria and Thrace. The Bulgarians lived in 350 AD. along the lower Danube in the Byzantine Empire south of the lower Danube. They were a mighty people, not only in Moesia but also in Thrace and Illyria."
- It is important that Tsenov's facts show that the Bulgarians have been in the Balkans since the 4th century, with which the author has even shaken the general opinion about the founding of the Bulgarian state in 679 by a handful of Mongol Bulgarians."
- "If historians who are able to check the facts admit their allegiance, we will have to change some of our beliefs about the origins of Germanism. We have to add that this book is abundant with documents and that some explanations, to say the Christianization of the Goths and the Huns, are very well documented and deserve serious attention."
- "In his present volume, Tsenov gives a careful and interesting account of the complex historical events in the second half of the first century, which preserves its value even if one disagrees with some of his claims." 
- "Tsenov is famous in Italy for his logical Bulgarian erudition, and in Germany, with his previous work, he has revolutionized the origin of the Bulgarians and the other Slavs in the Balkans.... The thesis on the Thracian-Bulgarian origin of the Bulgarians was supported by Tsenov with a great controversial liveliness, which is sometimes quite brave but always rests on arguments that can not be denied without an absolute competence since the author, who has devoted his entire life to this study, does not allow concessions.... He establishes in a complete picture Irvine inhabit life, the language of the Thracians and Illyrians, the ethnic influence that they exercised on the development of the conquering peoples in the Balkans. He concludes in the aboriginal character of the Bulgarians, which is comprehensively addressed and clearly and accurately exposed. All of the work has been examined with a critical chronological and convincing method. He deserves praise. Mr. Tsenov shows that he is a man who has a deep knowledge and a great skill and a man who has put all his love and his whole excitement, who is always inspired by a belief that undoubtedly gives him the right to delight.
- "Dr. Tsenov, who has been a lecturer at Berlin University for years, has a double merit. He again gives us a new composition on the oldest story of the Bulgarians, which, almost 50 years after the old history of Konstantin Irechek, occupies a prominent place. It brings the Bulgarians to the many difficult-to&reach Latin, Byzantine and Old Slavic sources. The origins of the Southeastern countries and church history are, in any case, set by Tsenov for us in Central Europe in a new light.
- The sources used by Tsenov are scarcely accessible to the average European because one wuld use their lifetime to search for them and to use them. Dr. Tsenov deserves approval, if only for the merit and the temperament with which he treats his work." 
- Ziezi ex quo Vulgares, "Забравеният д-р Ганчо Ценов"
- Hans Filipp, рецензия на "Die Abstammung der Bulgaren...", “Philologishe Wochenschrift”, Heft 10/11, 14 März 1931
- Prof. Mayer, “Indogermanische Forschungen”, Heft 2, 1933
- François Pique, Revue Germanique, Paris, 1936
- Dr. Victor Lebezelter, „Mitteilungen der Anthropologischen Gesellschaft”, Wien, 1936
- prof. dr. Antonio Baldaci, член на Италианската АН, сп. „Светоглас”, юни (June), 1937 г., стр. 6
- “Zeitschrift für Geopolitik”, Februar 1936
- “Europaische Revue”, Heft 4, 1936