1. Abramowitz M. & Stegun I. (1964) Handbook of Mathematical Functions
2. with Formulas Graphs and Mathematical Tables. United States department of
3. Commerce Library of Congress.
4. Balaji D. (2016) The effects of filtering on catchment scale GRACE solutions;
5. Water Resources Research. DOI: http://dx.doi.org/10.1002/2016WR018960