Bibliography

1

P. DuChateau and D.W. Zachmann.
Partial Differential Equations.
Schaum's Outline Series. McGraw-Hill, 1986.

2

M.R. Spiegel and J. Liu.
Mathematical Handbook of Formulas and Tables.
Schaum's Outline Series. McGraw-Hill, second edition, 1999.

cited: 18.2.3.2