<a href="https://en.wikipedia.org/wiki/Casting_defect" class="extiw" title="en:Casting defect">Casting ingot defects</a>. Comparison between killed steel and rimmed steel.
Reginald Bashforth G.
<a rel="nofollow" class="external text" href="https://archive.org/details/manufactureofiro029991mbp">The Manufacture Of Iron And Steel Vol II p.278</a>