<span class="citations"><p>Tethuharu Okazaki, Takeo Komukai, Saburo Uchikuga, "Process for preparing cysteamine-S-substituted compounds and derivatives thereof." U.S. Patent US4371472, issued September, 1969.</p>
</span><a href="https://www.google.com/?tbm=pts#q=4371472&amp;tbm=pts" rel="noopener" target="_blank">US4371472</a>