First and second printing apparatus are in an intranet and a bibliography server connected to the Internet. The bibliography server being configured to manage bibliographic information of print data. The first printing apparatus acquire a list of print data from the bibliography server, when an instruction to print out print data included in the list is received from a user with an operating unit of the first printing apparatus, sends identification information for identifying the print data to the second printing apparatus and when a print request is received, prints out print data included in the received print request. The second printing apparatus sends bibliographic information of print data received from an external apparatus to the bibliography server; and sends a print request containing the print data identified by the identification information to the first printing apparatus.