00642naa#a2200181#i#450# EN\\bibl\81877 20241124032027.7 2412-9186 20171225b2017####ek#y0engy0150####ca RUS RU Signals and interlocking development during imperialism (1906-1917). Part 4: Safety devices Journal article Saint-Petersburg FSBEI HE "Emperor Alexander I St. Petersburg State Transport University" 2017 10 с. Journal article local Меры безопасности. Сигналы. 656.25 RUS Lupal Nicolay V atjournal.ru