Let $K/\mathbb{Q}$ be a cyclic cubic eld with an prime conductor $ l $. In the paper it is given method for verification that $K$ is $\omega − good$ and it is applied for conductors to $l = 349$.
@article{255, title = {Note on sums of units in real cubic fields}, journal = {Tatra Mountains Mathematical Publications}, volume = {55}, year = {2013}, doi = {10.2478/tatra.v56i0.255}, language = {EN}, url = {http://dml.mathdoc.fr/item/255} }
Kostra, Juraj; Krčmarský, David. Note on sums of units in real cubic fields. Tatra Mountains Mathematical Publications, Tome 55 (2013) . doi : 10.2478/tatra.v56i0.255. http://gdmltest.u-ga.fr/item/255/