During the 1970s and 80s, when the first thorough fundamental studies with nanoparticles were underway in the United States by Granqvist and Buhrman and Japan within an ERATO Project, researchers used the term ultrafine particles. However, during the 1990s, before the National Nanotechnology Initiative was launched in the United States, the term nanoparticle had become more common, for example, see the same senior author's paper 20 years later addressing the same issue, lognormal distribution of sizes.