I got this book from a second hand book selling site relibrea.com. I was then looking for Geronimo Stilton books for my son; when I went to pick up my kid's books, talking to the seller about the books we were interested in I commented Hemingway's book. Suddenly the seller say "I think my son just finished that book at his classes at the university last year; let me grab it for you". I left the place with half a dozen books for kids, plus this one for me; and the seller refused to take my money. That is what book exchange places are really for: to let others enjoy the books you enjoyed.
The book story is one of guerrilla warfare -with a wider view of the war effort against fascism-, self-abandoment for the cause of the Republica (which sets the title for the book) and finally about whole life lived in just a few days.
From a formal perspective, it struck me the expression "obscentity in the milk" or the use of "obscenity" quite often in the book. That expression is truly a softened version of "shit in the milk", or "me cago en la leche" (common in spoken Spanish) which itself is an euphemism of "me cago en Dios" (a quite stronger expression, much seldom used in common Spanish talking). At first I thought it as a later editing of the book, but just found that it is Hemigway's original writing to avoid censorship from editors.