Harsojo, Dianto (2017) Analisis pengaruh variabel product quality, sales service quality, technical repair service support dan complaint handling service terhadap customer loyalty melalui trust in the supplier pada produk hars di Surabaya. Masters thesis, Universtitas Pelita Harapan.

Harsojo, Dianto (2016) Pengaruh construed external image of the company, perceived salesperson characteristics, perceived company characteristics terhadap customer extra role behaviors melalui customer company identification pada produk HARS di Surabaya. Bachelor thesis, 01120130051.