Drawn from one source. The salient features of the Indian Constitution include: the lengthiest written constitution, drawn from various sources, a blend of rigidity and flexibility, a federal system with a unitary bias, a parliamentary form of government, a synthesis of parliamentary sovereignty and judicial supremacy, rule of law, an integrated and independent judiciary. fundamental rights, directive principles of state policy, fundamental duties, secularism, single citizenship, judicial review, and the basic structure doctrine.