P. 197, line -1

Equation (6.7) should be:

$\xi (t)=c_1{\hat{\xi }}^1{e}^{{\lambda }_{1}t}+c_2{\hat{\xi }}^2{e}^{{\lambda }_{2}t}+\cdots +c_n{\hat{\xi }}^n{e}^{{\lambda }_{n}t}$

Return to errata.