Efendi, F., F. Kurniawan, and D. A. R. Wulandari. “THE EFFECT OF ADDITIVE WITH FOAM AGENT AND COCONUT SHELL ON LIGHTWEIGHT CONCRETE”. Neutron, Vol. 19, no. 1, July 2019, pp. 72 -79, http://ejournal.worldconference.id/index.php/neutron/article/view/79.