what did ivan pavlov invented?
Classical conditioning
contradiction
 Many similar experiments were pursued by Dziga Vertov in his 1931 Entuziazm and by Chaplin in Modern Times , a half @-@ decade later . 

neutral
 Ivan the Russian ( Bulgarian : Иван Русина , Ivan Rusina ; Hungarian : Orosz Iván ) ( fl . 1288 / 1323 – 1332 ) was a 14th @-@ century Bulgarian military leader of Russian origin who served Bulgarian tsars Michael Shishman and Ivan Alexander . Prior to joining the armed forces of the Second Bulgarian Empire , Ivan the Russian may have been a military commander in the service of the Hungarian governor of Severin . 

neutral
 This work was confirmed three years later at the Joint Institute for Nuclear Research at Dubna ( then in the Soviet Union ) . 

contradiction
 Tsar Ivan IV of Russia undertook in 1577 hostilities in the Livonian region , which resulted in his takeover of most of the area and caused the Polish – Lithuanian involvement in the Livonian War . The successful counter @-@ offensive led by King Báthory and Jan Zamoyski resulted in the peace of 1582 and the retaking of much of the territory contested with Russia , with the Swedish forces establishing themselves in the far north ( Estonia ) . Estonia was declared a part of the Commonwealth by Sigismund III in 1600 , which gave rise to a war with Sweden over Livonia ; the war lasted until 1611 without producing a definite outcome . 

contradiction
 Despite the teething problems with the MiG @-@ 3 , in 1941 , one of the aircraft 's designers — Mikhail Gurevich — was awarded the State Stalin Prize for his contribution to Soviet aviation . 
