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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Identical to the British issue of the same date except for the price marked on the cover. Details taken from Table of Contents. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Issue partially indexed - probably identical to the British issue of the same date except for the price marked on the cover. |   | 
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 Strictly speaking the first 18 issues were titled Street & Smith’s Unknown (UK) but as the magazine is universally known as Unknown (UK) it has been decided to index it as such. | 
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 Details supplied by Douglas Greene. |   | 
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 Title changed from Unknown (UK). | 
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