definiens: means ( a ) an independent, appropriately qualified Third Party expert at KPMG, Ernst & Young, Deloitte or PwC who is acceptable to both Parties or other Third Party expert mutually agreed by the Par ties or ( b ) if the Parties fail to agree on an inde pendent Third Party expert in accordance with the preceding claus e ( a ) within [ * * * ] after such request for referral, an independent, appropriately qualified Third Party ex pert at KPMG, Ernst & Young, Deloitte or PwC who is selected by mutual agreement of ( i ) an independent, appropriately qualified Third Party expert at KPMG, Ernst & Young, Deloitte or PwC selected by MedImmun e within [ * * * ] after such request for referral and ( ii ) an independent, appropriately * * * CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN T HIS DOCUMENT, MARKED BY [ * * * ], HAS BEEN OMITTED AND FILED SEPARATELY WITH T HE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 24B-2 OF THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED