source: The exchange of copies of this Agreement by electronic mail in "portable document format"  form or by other similar electronic means shall constitute effective execution and delivery of this Agreement and shall have the same effect as copies executed and delivered with original signatures.
target: The exchange of copies of this Agreement by electronic mail comes in "portable document format" form or other similar electronic means. The exchange of copies shall constitute effective execution and delivery of this Agreement. The exchange shall have the same effect as copies executed and delivered with original signatures.
references: The exchange of copies of this Agreement by electronic mail comes in "portable document format" form or other similar electronic means. The exchange of copies shall constitute effective execution and delivery of this Agreement. The exchange shall have the same effect as copies executed and delivered with original signatures.