"A study of the green auroral line by the interference method."

MM : Mass Market Paperback. Often thought of as the pocket paperback.

wrappers : Paperback or softbound. Also, wraps.

plates : Full page illustrations or photographs. Plates are printed separately from the text of the book, and bound in at production. I.e., they are not sewn as parts of gatherings.

8vo : Short for Octavo, A book whose page size is approximately 8-10 inches tall. The size is based on a sheet of paper 25 inches by 38 inches, the size of paper traditionally used by book printers, which has been folded and cut into 16 pages.. Unfortunately often misunderstood to mean 8 volumes.