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Roberts N, Cruz-Orive LM, Reid NM, Brodie DA, Bourne M, Edwards RH.Roberts N, et al.J Microsc. 1993 Sep;171(Pt 3):239-53. doi: 10.1111/j.1365-2818.1993.tb03381.x.J Microsc. 1993.PMID: 8246272