The following abbreviations are commonly used in referring to the Classical writers and texts.
Ca. = refers to Charaka Samhita
Su. = refers to Sushruta Samhita
A.S. = refers to Astanga Sangraha
A.H. = refers to Astanga Hridayam
Sharng = refers to Sharngadhara Samhita
Ma. Ni. = refers to Madhava Nidanam Samhita
B.P = Bhava Prakasha of Bhava Mishra Samhita