. "http://en.wikipedia.org/wiki/Quantum_number"^^ . . . . "The \"Principal Quantum Number\" describes the electron shell, or energy level, of an atom. The value of \\(n\\) ranges from 1 to the shell containing the outermost electron of that atom."^^ . "Orbital Angular Momentum Quantum Number"@en . . "l" . "\\(l^2 = \\hbar^2 l(l + 1), l = 0, 1, ..., n - 1\\), where \\(l_i\\) refers to a specific particle \\(i\\)."^^ . . . "http://www.iso.org/iso/catalogue_detail?csnumber=31894"^^ . .