TY  - RPRT
TI  - A study of alternative schemes for extrapolation of secular variation at observatories
AU  - L.R. Alldredge
PY  - 1976
DO  - 10.1016/0031-9201(76)90015-7
UR  - https://pubs.usgs.gov/publication/70010426
ID  - 70010426
ER  -