1.Proof of the economic operator's economic and financial standing may, as a general rule, be furnished by one or more of the following references:
(a)appropriate statements from banks or, where appropriate, evidence of relevant professional risk indemnity insurance;
(b)the presentation of balance-sheets or extracts from the balance-sheets, where publication of the balance-sheet is required under the law of the country in which the economic operator is established;
(c)a statement of the undertaking's overall turnover and, where appropriate, of turnover in the area covered by the contract for a maximum of the last three financial years available, depending on the date on which the undertaking was set up or the economic operator started trading, as far as the information on these turnovers is available.
2.An economic operator may, where appropriate and for a particular contract, rely on the capacities of other entities, regardless of the legal nature of the links which it has with them. It must in that case prove to the contracting authority that it will have at its disposal the resources necessary, for example, by producing an undertaking by those entities to that effect.
3.Under the same conditions, a group of economic operators as referred to in Article 4 may rely on the capacities of participants in the group or of other entities.
4.Contracting authorities shall specify, in the contract notice or in the invitation to tender, which reference or references mentioned in paragraph 1 they have chosen and which other references must be provided.
5.If, for any valid reason, the economic operator is unable to provide the references requested by the contracting authority, he may prove his economic and financial standing by any other document which the contracting authority considers appropriate.