Mochida, Rivkin, Gil, Kierszenbaum: "Keratin 9 is a component of the perinuclear ring of the manchette of rat spermatids." in: Developmental biology, Vol. 227, Issue 2, pp. 510-9, 2000 (PubMed).
Swensson, Langbein, McMillan, Stevens, Leigh, McLean, Lane, Eady: "Specialized keratin expression pattern in human ridged skin as an adaptation to high physical stress." in: The British journal of dermatology, Vol. 139, Issue 5, pp. 767-75, 1999 (PubMed).
Langbein, Heid, Moll, Franke: "Molecular characterization of the body site-specific human epidermal cytokeratin 9: cDNA cloning, amino acid sequence, and tissue specificity of gene expression." in: Differentiation; research in biological diversity, Vol. 55, Issue 1, pp. 57-71, 1994 (PubMed).