Bhuvaneshvari Yantra along with its Mool Mantra is considered very effective medium to fulfil Bhuvaneshvari Sadhana.
ॐ ऐं ह्रीं श्रीं नमः॥
Om Aim Hreem Shreem Namah॥
Ashtottara Shatanamavali of Bhuvaneshvari
list of Bhuvaneshvari Mantras
information on Goddess Bhuvaneshvari
10 forms of Shakti