Robert Sonneman's
name will come up in dozens of wholesale and retail sites if you follow Vivienne's advise...
Robert used to design for George Kovacs the designer/entrepreneur that brought Kartell to the U.S. but that is mostly known for innovative design and more recently for information sysytems on new (and old) materials.
Robert Sonneman design studio still designs and produces a large number of lighting fixtures but I doubt that this is one of them. I could be wrong but Robert's Designs are not as heavy and are defenitly more elegant. Have you looked at the labels on the sockets? U.L. approuval labels usually mention the manufacturer or at least his code. You can call U.L. (Underwriters Laboratory) and ask the name behind the code. Good luck!!
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