Widjaja, Paul Raymond (2009) Analisis Perilaku Overreaction Investor terhadap Informasi Keuangan dan Return Saham Badan Usaha yang Terdaftar di BEI Periode 2003-2008. [Undergraduate thesis]
Purnamadewi, Fanny and ., David and Widjaja, Paul Raymond (2008) Balanced Scorecard. Universitas Surabaya. (Unpublished)