Michael Rothstein, B. F. Caviness. A structure theorem for exponential and primitive functions a preliminary report. ACM Comm. Computer Algebra, 10(4):25-28, 1976. [doi]
@article{RothsteinC76,
title = {A structure theorem for exponential and primitive functions a preliminary report},
author = {Michael Rothstein and B. F. Caviness},
year = {1976},
doi = {10.1145/1088222.1088225},
url = {http://doi.acm.org/10.1145/1088222.1088225},
researchr = {https://researchr.org/publication/RothsteinC76},
cites = {0},
citedby = {0},
journal = {ACM Comm. Computer Algebra},
volume = {10},
number = {4},
pages = {25-28},
}