How to farm for 'Yellow Backbone' & 'Tomb Mould (5)'?

I've just finished the lower loran dungeon and received the 'lower loran root chalice'. Now, I wish to make an FRC LLR chalice but I'm short of 'yellow backbone' and 'tomb mould(5). How/where I can farm these easily? I've seen a few farming videos on youtube but they are all for either Pthumerian IIyl or Isz chalices which I haven't started yet. I've only done the standard Pthumeru till defiled challice. What are my choices? Thanks in advance.