Tribological characterization of sponge gourd outer skin fiber-reinforced epoxy composite with Tamarindus indica seed filler addition using the Box–Behnken method oleh Arockiasamy Felix Sahayaraj, Muthukrishnan Mayakrishnan, Iyyadurai Jenish, Kaliappan Seeniappan, Lakshmaiya Natrayan, Djearamane Sinouvassane, Tey Lai-Hock, Wong Ling Shing, Kayarohanam Saminathan, Obaid Sami Al, Alfarraj Saleh, Sivakumar Subpiramaniyam