The idea of ResNets, HighwayNets, and DenseNets revolves around addressing the vanishing gradient problem. If you are not familiar with that term, or would like to refresh your definition, check out the first link below. Also check out the next topic which is General Adversarial Networks.
Blog: (2)
“What is the vanishing gradient problem?”
https://www.quora.com/What-is-the-vanishing-gradient-problem
“ResNets, HighwayNets, and DenseNets, Oh My!”
https://chatbotslife.com/resnets-highwaynets-and-densenets-oh-my-9bb15918ee32
Papers: (1)
“General Adversarial Networks”
https://arxiv.org/pdf/1406.2661.pdf