This article contains several mistakes.
Atoms are made up by neutrons, protons and electrons. Neutrons and protons are made up by quarks. Electrons are not, they are really elementary (see respective article). Then the article lists a whole bunch of other terms: "pions, gluons, hadrons, etc". Those are different types of particles which cannot be listed like that without any further information. Pions are not constituents of protons or neutrons. Hadron is the collective term for protons, neutrons and other particles.