@misc{102921, author = {Marjorie McClain and Christoph Witzgall}, title = {Surface Energy Formula for a Hsieh-Clough-Tocher Element}, year = {1999}, month = {1999-01-01}, publisher = {NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD}, language = {en}, }