1. Bellingham and Stanley, 61 Markfield Road, London N15, UK
2. Slides supplied by Oil Care Ltd, Racecourse Road, Pershore, Worcs, UK
3. Biocides for use in oil emulsions - Selection techniques for rolling mill coolants and cutting fluids;Hill;Trib. Int.,1976
4. Merckoquant Nitrite papers supplied by The British Drug House Ltd, Poole, Dorset, UK
5. Grotan BK supplied by Sterling Industrial, Chapeltown, Sheffield, UK