<span class="citations"><p>Hiroitsu Kawata, Tadayoshi Ohmura, Katsuhiko Yano, Mikio Matsumura, Saburo Higuchi, Yoshiaki Soeishi, "Nifedipine-containing solid preparation composition." U.S. Patent US4412986, issued November, 1976.</p>
</span><a href="https://www.google.com/?tbm=pts#q=4412986&amp;tbm=pts" rel="noopener" target="_blank">US4412986</a>