13.
Ferreira M. M. C., Porto M. E. G., “Uma Química Quântica Visual: Unindo o Útil ao Agradável”. [“Visual Quantum Chemistry: Putting together Useful and Pleasant”] Quím. Nova, 16, 589-595, (1993).

cover pagejournal information pagethe cover picture (from this work)

High resolution Figures:

Figure 2, p. 590Figure 3, p. 591Figure 5, p. 593Figure 6, p. 594Figure 7, p. 595