Steven C. Shaffer. Ludwig: an online programming tutoring and assessment system. ACM SIGCSE Bulletin, 37(2):56-60, 2005. [doi]
@article{Shaffer05,
title = {Ludwig: an online programming tutoring and assessment system},
author = {Steven C. Shaffer},
year = {2005},
doi = {10.1145/1083431.1083464},
url = {http://doi.acm.org/10.1145/1083431.1083464},
researchr = {https://researchr.org/publication/Shaffer05},
cites = {0},
citedby = {0},
journal = {ACM SIGCSE Bulletin},
volume = {37},
number = {2},
pages = {56-60},
}