You can find high-quality PDF scans of all parts on the Internet Archive Raga Nidhi (Volumes 1–4) by B. Subba Rao
Most books use .
If you want the , look for Deepak Raja's writings on the philosophy of Bandish . If you want the PDF Book , look for "Bhatkhande Kramik Pustak Malika PDF" —this is the ultimate source for Raag Bandish notation. raag bandish books pdf