Early evolution of photosynthesis: clues from nitrogenase and chlorophyll iron proteins.
Proc Natl Acad Sci U S A. 1993 Aug 1;90(15):7134-8. doi: 10.1073/pnas.90.15.7134.
Proc Natl Acad Sci U S A. 1993.
PMID: 8346226
Free PMC article.