Minkus catalogues are obsolete
It is probably OK to purchase this catalogue as a reference work or piece of stamp collecting memorabilia, but do not build your collection using the Minkus numbering system. Amos Press, the publisher of the Scott Stamp Catalogue, purchased the rights to the Minkus catalogue and the Minkus numbering system in 2004. You will never see another edition of these Krause-Minkus catalogue published. Too bad, because the Minkus catalogue contained details for some stamp varieties not listed in Scott.