Whether you're talking about balanced or unbalanced lines, the best references are those that discuss transmission lines from an engineering perspective. Most studies or reference materials deal with their behaviors at RF frequencies where the issues are greater. As we get nearer to DC, obviously the issues are more and more limited to simple DC resistance.Pick up a college textbook on transmission lines. Forget the forum discussions, sales rhetoric and rantings. After you've perused an engineering textbook, you probably won't care to enter into forum discussions about audio cables.