Dates of the 9/11 hijackers' entry to America

Does anyone know of any good, non-biased (obviously) cites as to the 9/11 hijackers’ dates of entry to America? If these included the dates and places they went to flight school, that would be a bonus, but those aren’t necessary.

I’ve searched GQ and Google, but didn’t really see anything satisfactory.

Thanks.

This site has scans of some of their visa applications. They are stamped with the dates they were received, and you can see the “Date you intend to arrive in the USA” boxes. Whether these correspond with their actual entry dates is unclear.