Answers based on econometric references will be greatly enjoyed!
For starters:
Granger, C.W.J. and Joyeux, R. (1980), AN INTRODUCTION TO LONG‐MEMORY TIME SERIES MODELS AND FRACTIONAL DIFFERENCING. Journal of Time Series Analysis, 1: 15-29.
C.W.J. Granger, Long memory relationships and the aggregation of dynamic models, Journal of Econometrics, Volume 14, Issue 2, 1980, Pages 227-238.