I only own one of Leo Baca's books but have search most of them at libraries. The introduction to the books may in part answer your question. This is part of the introduction to Volume VIII - Czech Immigration Passenger Lists Baltimore 1834-1879 "Volume VIII documents the arrival of Czech immgrants in Baltimore during 1834-1879. I was able to identify 28,125 arrivals in Baltimore during this time period. All of their names were abstracted from 31 rolls of National Archives microfilm. The follow is a summary by year of those that were abstracted:" He then lists the number of names he found for each year from 1834 to 1879. Then the introduction continues with "Every attempt has been made to make those abstracts as complete as posible. None the less, there are significant problems. Besides the usual problem with spelling, Czech arrivals who gave their country of origin as Germany gave me considerable difficulties. In addition, Czechs who had Germanic sounding names and who listed Germany or Austria as their country of origin will probably be omitted. . . ." So if a passenger arrival indicated Russia as there country of origin, I doubt Leo even considered including them on the list. If you've every done much work with microfilm rolls back at this time, the "usual problem with spelling" can really be quite an issue. Some lists seem to have faded signifacantly and are very difficult to read. Some of the ships captains (usually German) handwritting and spelling script is difficult to understand even when names were spelled correctly not to mention the problem of misspelled names. If your Czech name had a German spelling equivlant, often the name was record in its German form since that was the offical language of the Austrian Empire (which included Bohemia & Moravia) during this time period. I have been very forturate to find most but not all of my ancestors in Baca's lists, but some were not were I thought they'd be. For example, A Shavlik (as it's spelled here in America would have been spelled S'avlik (with a hacek over the S) when written in Czech, but was found under Schawlik, its German form. I also found in Baca's lists brother to my Kruta ancestor that came on the same ship listed as Bruta. On the original document, the script the captain used, the K and B are quite similar and if you're not really sure what you are looking for, it is easy to miss them.