F. H. Hilliard 
Buddha, The Prophet and the Christ [PDF ebook] 

Originally published in 1956, this book brings together from the canonical writings of Buddhism, Islam and Christianity the most important of the passages in which the view of the Founder is reflected. It aims to let each of the sacred traditions tell its own story and only such comments have been added as seem necessary to bring out the full significance of the passage quoted. The final chapter summarizes some of the difficult questions which arise from a comparison of the extracts from the 3 traditions.