In June 1977, two well-known Soviet researchers, Igor Sobel'man, and Vladilen Letokhov, displayed a film exposed to the output of plasmas of chlorine, calcium and titanium, similar to the Utah results. They were careful to point out that the results were very preliminary and further study was required. Over the next few years, a small number of additional papers on the topic were presented. The most direct of these was Sobel'man's statements at a 1979 conference in Novosibirsk when he said he was observing lasing in a calcium plasma. As with earlier announcements, these results were met with skepticism.