This is a survey paper that presents, as it title says, 20 large mosques built in Russian Federation in the past 20 years. There is nothing wrong with such an approach except that the paper verbally describes all the details of these religious structures and offers NO visual reports. This is not acceptable for a survey effort, especially in a field like architecture. Additionally, while some of the discussion is instructive, there is little offered in terms of analysis and conclusions. A typological and stylistic study using some sort of matrix to show the various mosques quickly and effectively would be a necessary addition. Also, providing a map with the geography of the different nations and cities would be very helpful.
My recommendation is to reject the paper ... there is little or no time to improve it in the ways i am recommending. However, i'd recommend the author to develop it and, when properly completed, present/publish it in a different conference or submit it to a journal