Analisis yuridis terhadap pelelangan barang/jasa dalam perkara persekongkolan tender menurut hukum persaingan usaha (studi putusan KPPU N0.04/KPPU-L/2005 dan putusan N0.17/KPPU-L/2007) = Juridical analysis on the goods/services tender in the tender conspiracy case according to business competition law (Study on number 04/KPPU-L/2005 and number 17/KPPU- L/2007 KPPU verdicts)