Pengembangan Metode Pengukuran Standar Volume Pekerjaan Design Development, Sitework dan Struktur Berbasis Wbs pada Kawasan Stadion Bangunan Khusus Gedung Negara Dengan Kontrak Terintegrasi Rancang dan Bangun untuk Meningkatkan Akurasi Perhitungan Volume = Development of Standard Measurement Method Based on WBS for Design Development, Sitework and Structural Work Volume of Stadium Area of Special State Building with Integrated Design Build Contract to Increase Accuracy of Work Volume Measurement