Hello Lal,
The links under the Mahā Satipaṭṭhāna Sutta section cannot be found:
Satipaṭṭhāna Sutta – Structure
Satipaṭṭhāna – Introduction
Kāyānupassanā – Section on Postures (Iriyapathapabba)
Kāyānupassanā – The Section on Habits (Sampajanapabba)
Prerequisites for the Satipaṭṭhāna Bhavana
What is “Kaya” in Kāyānupassanā?