TY  - RPRT
TI  - Approximation for age-structured population models using projection methods.
AU  - T H Barr
PY  - 1991
DO  - 10.1016/0898-1221(91)90213-n
UR  - https://pubmed.ncbi.nlm.nih.gov/12284707/
ID  - 12284707
ER  -