- 1Reference: IG1/6
Title: Assignment between the Donovan Electrical Co Ltd, Elstow Road, Bedford, and Brookhirst Igranic Ltd, ...
Level of description: item
Date Free Text: 1972
Production date: From: 1972 To: 1972 - 2Reference: IG2/2
Title: Patents file containing printed copies of related patents (including some of Brookhirst and Donovan)...
Level of description: item
Date Free Text: 1899-1944
Production date: From: 1899 To: 1944 - 3Reference: IG3/4
Title: Ceased patents of the Donovan Electric Co, Birmingham
Level of description: series
Date Free Text: 1948-64
Production date: From: 1948 To: 1964