good books on superclusters and voids?? I have been searching for a good undergraduate to advanced level book on galaxy clusters , dark matter , superclusters and voids and I have yet to find any. I have found however the scientific American library book " the dark matter and cosmic web story" but I am hesitant to purchase it is expensive and I do not know if it is more of an historical book or a book for study. I am looking for a good book that will give me the equations , data and necessary study on the subjects. Not just an overview of the subject for the lay person. I was really looking for studies on the sloan great wall super cluster , voids , the cosmic web ( large scale structure ) just basically what the title of the thread states.