1. E. Ott ..Cellulose, Chap. III, Interscience Publishers, 1946.
2. P. H. Hermans..Physics and Chemistry of Cellulose Fibres, Second Part, Elsevier, 1949.
3. G.L.Clark ..Applied X-Rays, Chap. XXIII, McGraw-Hill, 1940.
4. A. Frey-Wyssling..Sub-Microscopic Morphology of Protoplasm and Its Derivatives, pp. 193–203, Elsevier, 1948.