TY  - RPRT
TI  - Measuring urban problems: a brief report on rating grass coverage.
AU  - E R Christophersen
AU  - L A Doke
AU  - D O Messmer
AU  - T R Risley
PY  - 1975
DO  - 10.1901/jaba.1975.8-230
UR  - https://pubmed.ncbi.nlm.nih.gov/16795496/
ID  - 16795496
ER  -