- Substituted Silicon Nitride Products and Method Thereof Derek P. Thompson, Hasan Mandal, Yi-Bing Cheng WO 94/17010, 4 August 1994
- Heat Treatment of Nitrogen Ceramics Derek P. Thompson, Hasan Mandal WO 94/07811, 14 April 1994
- Multication Doped Alpha-Beta SiAlON Ceramics Hasan Mandal, Ferhat Kara, Servet Turan, Alpagut Kara PCT No: PCT/TR02/00006 (Feb. 2002) US Patent No: US 7,064,095 B2 EP Patent No: 1 414 580 B1
- Silicon Nitride Ceramics with Improved Wear Resistance and Production Method Therefore Hasan Mandal, Ferhat Kara, Servet Turan, Alpagut Kara WO2013EP60197 20130516 WO2013171324
- Doped Alpha-Beta-SiAlON Ceramic Materials Bernd Bitterlich, Kilian Friederich, Hasan Mandal, Ferhat Kara, Servet Turan, Alpagut Kara WO2010EP67496 20101115 WO2011058176
- SiAlON Ceramics Hasan Mandal, Ferhat Kara, Servet Turan, Alpagut Kara EP12182818.0, OZ12022EP-Q3/BR, 03 September 2012