Analisis dugaan penetapan harga dan kartel yang menimbulkan persaingan usaha yang tidak sehat : studi kasus kartel semen putusan KPPU No. 01/KPPU-I/2010 dan Peraturan Komisi No. 4 Tahun 2010 = Analysis of presumption price fixing and cartel practices that evoke unfair business competition : case study of cemen cartel on commission for the supervision of business competition Republic of Indonesia-KPPU RI decision number 01/KPPU-I/2010 and commission regulation number 4 year 2010 (Fakultas Hukum Universitas Indonesia, 2011)