https://www.academia.edu/19518931/observasi_PT_CV_FIRMA_UD
http://www.hukumonline.com/klinik/detail/cl3286/mendirikan-usaha-dagang-(ud)
https://wiwidtrylestari.wordpress.com/2015/11/12/pengertian-badan-usahaperbedaan-cv-pt-pte-ltd-inc-corp-mnc-tbk-ud-sdn-bhd-nv-firma-koperasi-yayasan/
http://msainunamaliah.blogspot.co.id/2016/11/tugas-2-pengantar-bisnis-informatika.html
