The rather unusual part of "Prapanchasara-Tantra" by Shankaracharya is the Chapter about Shreekara-Mantra. As far as I remember Vaishnava-Sarga of "Shree Sharada-Tilaka-Tantram" also contains the chapter about Shreekara-Mantra:
Dhyanam (yes, very beautiful - Aishwarya-CharurBhuja Bhagavan Shree Vishnu and Mukuta!):
Green screenshot from
Hindi edition of "Prapanchasara-Tantram"
