galloshes

hi all, i have been asked to reduce access to read and print only on a resource in an external non transitive trusted domain. we log on to domain a and access a resource in domain b. when I look at ntfs permissions on relevant files and folders in domain b I can not work out how access is provided currently. there are no explicitly listed permissions listing accounts in domain A for me to edit- any ideas of where to keep looking- i'm assuming this is something to do with the trust? thanks