I think the j learning materials are best, particularly 'learning j' (https://www.jsoftware.com/help/learning/contents.htm https://www.jsoftware.com/help/learni

I think the j learning materials are best, particularly 'learning j' (https://www.jsoftware.com/help/learning/contents.htm https://www.jsoftware.com/help/learning/contents.htm), though others like 'j for c programmers' (https://www.jsoftware.com/help/jforc/contents.htm https://www.jsoftware.com/help/jforc/contents.htm).