Billings birth control

"In Western countries, in fact, natural methods have continued to be considered not only completely ineffective, but also inconvenient and difficult to apply. And there is another characteristic, which is never mentioned, that has contributed to giving them a bad name: the fact that they are free. No pharmaceutical company had any interest in financing research on this form of birth control. Instead, it was to their advantage to heap ridicule on it and discredit it".