Karel Culík. What is a flowchart loop and about structured programming. SIGPLAN Notices, 15(1):45-57, 1980. [doi]
@article{Culik80, title = {What is a flowchart loop and about structured programming}, author = {Karel Culík}, year = {1980}, doi = {10.1145/954127.954131}, url = {https://doi.org/10.1145/954127.954131}, researchr = {https://researchr.org/publication/Culik80}, cites = {0}, citedby = {0}, journal = {SIGPLAN Notices}, volume = {15}, number = {1}, pages = {45-57}, }