What were the causes of ww1 -short-term and long-term- and to what extent was germany to blame for the outbreak of the war?

the reason america came into ww1 because Germany sunk a couple of ships that had america citizens on it one very famous the lusitania and cause the united states to enter the war this was one of the long term events. the other reason that started the war was the assassination of  Austria Archduke Franz Ferdinand which caused the start of the war look at this web site and it will tell you every thing you need to know hope this helps
https://medium.com/@dhireshnathwani/what-was-the-most-significant-cause-of-world-war-one-ww1-74bb9e8... 

Primary sources are usually  more accurate and are written by someone who experienced it or witnessed it. secondary sources are those who heard of it after the fact that can lose details and or twist the event in a light that benefits them.