Reference

Optimization Methods
hhj()	Hall, Horowitz, and Jing (1995) "HHJ" Algorithm to Select the Optimal Block-Length
pwsd()	Politis and White (2004) Spectral Density "PWSD" Automatic Block-Length Selection
S3 Plot Methods
plot(<hhj>)	Plot MSE Function for HHJ Algorithm
plot(<pwsd>)	Plot Correlogram for Politis and White Auto\(-\)Correlation Implied Hypothesis Test