Walter McCrone说”每个化合物都有不同的形态，通常，对于所知的某一化合物的形态取决于对其投入的时间和金钱。“学术何尝不是，敏锐的眼睛判断重要性，优先级，潜在价值很必要。继续努力。

https://en.wikipedia.org/wiki/Polymorphism_(materials_science)#cite_note-11

Walter McCrone stated that "every compound has different polymorphic forms, and that, in general, the number of forms known for a given compound is proportional to the time and money spent in research on that compound."

 W. C. McCrone, in Physics and Chemistry of the Organic Solid State, eds. D. Fox, M. M. Labes and A. Weissberger, Interscience Publishers, London, 1965, vol. 2, pp. 725-767.