what is nordic/swedish/northern style

Every now and then I find a reference to a nordic style crossbow; what is this, how is it different from a German/central European style?

Nordic style stocks:  Geezer here: I can't claim to be an expert, but I've been researching and building crossbows for the last 40 years, so here's my take.  The 'nordic' bows I have seen (Finnish, Swedish,Norwegian) tend to have long, slender stocks, very much like earlier (13-15th century) Germanic bows.  Most of these stocks are more or less oval in cross-section, again like the German bows, with the possible exception of Norwegian bows, some of which have rectangular sections, like Spanish/Italian crossbows... particularly the two Maximilian I bows in the Kunsthistorisches Museum in Vienna (Wien) I suspect the difference in cross section may have something to do with trade-routes.  Germanic crossbows traded across the Baltic tend to influence Swedish/Finnish bows, whereas Norwegians are probably trading with western shippers operating along the European west coast.  But that's just my hypothesis.  I have no solid information to back it up.  
So in answer to your original comment.  Yes, Swedish and Finnish crossbows tend toward long, thin stocks with enlarged heads, usually rounded or oval in section, like German bows.  But Norwegian bows may be rectangular in section.  Geezer... my two bits worth.

Thanks Geezer, that's a really clear explanation, much obliged.