Out of print.

From the publisher:

Volume Four of Archie Goodwin and Al Williamson's definitive run on Secret Agent X9 continues its break neck pace as agent Phil Corrigan dives head first into ever more thrilling and outrageous adventures! Beginning on November 4th, 1974 and reproducing every gorgeously drawn strip until June 11th, 1977, each scanned from Al Williamson's own personal set of syndicate proofs -- more than 800 strips in all!

This came from the library of Burny Mattinson (1935-2023), an animator, director, producer, and story artist for Walt Disney Animation Studios, from 1953 until his death in 2023. Mattinson directed Mickey's Christmas Carol and The Great Mouse Detective. He was named a Disney Legend in 2008 and was the longest serving employee of The Walt Disney Company, with a career that spanned almost 70 years. His extensive library included numerous subjects and especially large collections of books on Disney, animation, and classic comic strips.