Encumbrances on making calls charged to a card can be reduced by a) storing information so that an association is created relating a card number and at least one calling telephone station, from which card calls charged to the associated card are to be made, b) using the association to retrieve ...http://www.google.de/patents/US5675607?utm_source=gb-gplus-sharePatent US5675607 - Method and apparatus for facilitating the making of card calls
