You could start by reading about the topic on Wikipedia (that will also refer you to many other sources.) Of course you could say that probably most of those articles and their sources were written by non-Muslims. But that is like saying that most people who have argued for any position have tended to be people who believe that position, and therefore we should ignore their arguments.
Just because there’s an article on the spread of Islam doesn’t mean that a balanced quantitative analysis on the means of its proliferation either exists or is possible. Usually when someone asserts something to that effect, the onus is on them to support their assertion by referencing a specific source.
You could start by reading about the topic on Wikipedia (that will also refer you to many other sources.) Of course you could say that probably most of those articles and their sources were written by non-Muslims. But that is like saying that most people who have argued for any position have tended to be people who believe that position, and therefore we should ignore their arguments.
reading about the topic on Wikipedia
Just because there’s an article on the spread of Islam doesn’t mean that a balanced quantitative analysis on the means of its proliferation either exists or is possible. Usually when someone asserts something to that effect, the onus is on them to support their assertion by referencing a specific source.