Third (Level 3 = तृतीया दिक्षा = तृ. दी.) in a series of books (or book sets) called 'Teach Yourself Samskrit (TYS)' or 'संस्कृतस्वाध्यायः (सं.स्वा.)' published by Rashtriya Samskrit Samsthan in collaboration with Samskrita Bharati.