Thanks. Anymore papers about the conception of GR around 1915?
I wanna see what was the exact motivation to propose the now known Einstein equations. The GR paper in the above paper is not too analytic about it. Especially I would love to see the 'false start' of GR in 1913.
If you get really desperate, you can investigate Einstein's collected papers, published by Princeton University Press. The hardbound volumes contain the original German versions, but there are also corresponding paperback volumes with English translations. Check your local university library or search for "collected papers of albert einstein" on amazon.com.
To find out about his original motivation and thought processes, you might have to study his letters to colleagues and friends.