Listing external users with access to team sites on O365

Hi,

Over the course of the past period, several users external to my organisation have received access to our company"s sharepoint team sites (as member or as visitor) on O365

How can I obtain a list of these external users (with their name and email address and the last connection date) ?
How can I obtain a list of external people who have been sent a sharing invitation but have not accepted it ? Can I cancel these invitations (these users do not appear in the member group until they accept the invitation, so I cannot remove them)

Thanks in advance,

Stephane