p24: - change “If a time series models exhibits serial correlation…” to “If a time series residuals exhibits…” - correct “b1 must be less than zero” in “|b1| must be less than one” (already mentionned in this forum) - correct “If b1 is equal to zero, there is a unit root.” in “If b1 is equal to one, there is a unit root.” Also, note that there is a mean reversion limit only when |b1| < 1