[1] Birkhoff G., MacLane S.: A Survey of Modern Algebra. Revised Edition, Macmillan Company, N. Y., 1954.

[2] Brand L.: Vector and Tensor Analysis. John Wiley & Sons, N. Y., 1957. MR 0021449

[3] Dickson L. E.: Modern Algebraic Theories. Benj. H. Sanborn & Co., 1926.

[4] Eisenhart L. P.: An Introduction to Differential Geometry. Princeton University Press, 1947. MR 0003048 | Zbl 0033.01801

[5] Forsythe A. R.: A Treatise on Differential Equations. Third Edition, Macmillan and Co., London, 1903.

[6] Fueter R.: Die Functionentheorie der Differentialgleichungen $\Delta u=0$ und $\Delta \Delta u = 0$ mit vier reelen Variablen. Commentarii Mathematici Helvetici, Vol. 7, Fas. 4, pp. 307-330, 1934-35. DOI 10.1007/BF01292723 | MR 1509515

[7] Fueter R.: Die Singularitäten der eindeutigen regulären Functionen einer Quaternionen-variablen 1. Commentarii Mathematici Helvetici, Vol. 9, Fas. 4, pp. 320-334, 1936-37. DOI 10.1007/BF01258196 | MR 1509562

[8] Fueter R.: Integralsätze für reguläre Funktionen einer Quaternionen-Variablen. Commentarii Mathematici Helvetici, Vol. 10, Fas. 4, pp. 306-315, 1937-38. DOI 10.1007/BF01214299 | MR 1509583

[9] Fueter R.: Über die analytische Darstellung der regulären Funktionen einer Quaternionen-variablen. Commentarii Mathematici Helvetici, Vol. 8, Fas. 4, pp. 371 - 381, 1935 - 36. MR 1509533

[10] Knopp K.: Theory of Functions. Part I, Elements of the General Theory of Analytic Functions. Translated from the Fifth German Edition, Dover Publications, N. Y., 1945. MR 0012656

[11] Krzywoblocki v. M. Z.: On the Stream Functions in Nonsteady Three-Dimensional Flow. Journal of the Aeronautical Sciences, Readers' Forum, Vol. 25, No. 1, p. 67, Jan. 1958.

[12] Lamb, Sir H.: Hydrodynamics. Sixth Edition, University Press, Cambridge 1932.

[13] Milne-Thompson L. M.: Theoretical Hydrodynamics. Macmillan & Co., London 1938.

[14] Misicu M.: Revolvarea Unor Probleme de Echilibru in Spatiu a Mediilor Continue. Part I, Procedee de Calcul cu Functii Cauternionice. Communicările Academiei R. P. R., Mecanică Aplicată, Tomul VI, pp. 72-81, Nov. 1956.

[15] Misicu M.: Revolvarea Unor Probleme de Echilibru in Spatiu a Mediilor Continue. Part II, Reprezentarea Miscării Fluidelor Ideale Imcompressible. Ibid., pp. 82-87.

[16] Reulos R.: Recherches Sur La Théorie des Corpuscules. Annales de L'Institut Fourier, L'Université de Grenoble, Tome V, 1953 et 1954.

[17] Rose A.: On the use of a complex (Quaternion) velocity potential in three dimensions. Commentarii Mathematici Helvetici, Vol. 24, Fas. 2, pp. 135-148, 1950-51. DOI 10.1007/BF02567029 | MR 0038182 | Zbl 0038.05703

[18] Skobelkin V. I.: Variational Principles in Hydrodynamics. Soviet Physics J. E. T. P., Vol. 4, No 1, pp. 68-72, Feb. 1957, Published by the American Institute of Physics Inc. MR 0121017

[19] Streeter V. L.: Fluid Dynamics. First Edition, McGraw-Hill, N. Y., 1948. MR 0028137 | Zbl 0038.37802

[20] Struik D. J.: Lectures on Classical Differential Geometry. Addison-Wesley Publishing Co., Inc., Mass., 1957. MR 0036551