I have come across three variations of Mahā-Mṛtyunjaya Mantra. One is the Popular Version, then there is a Long Version and the other is called as the Short Version.
Here goes,
"Popular Version" of Mahā-Mṛtyunjaya Mantra:
ॐ त्र्य॑म्बकं यजामहे सु॒गन्धिं॑ पुष्टि॒वर्ध॑नम् ।
उ॒र्वा॒रु॒कमि॑व॒ बन्ध॑नान् मृ॒त्योर्मु॑क्षीय॒ माऽमृता॑॑त् ।।oṃ tryámbakaṃ yajāmahe sughandhíṃ puṣṭivardhánam ।
urvārukam iva bandhánān mṛtyor mukṣīya māmṛtāt ॥
The longer version (संपूर्ण मंत्र), annotates one line each both in the beginning and the end of the Popular Version:
ॐ हौं जूं सः ॐ भूर्भुवः स्वः।
ॐ त्र्य॑म्बकं यजामहे सु॒गन्धिं॑ पुष्टि॒वर्ध॑नम् ।
उ॒र्वा॒रु॒कमि॑व॒ बन्ध॑नान् मृ॒त्योर्मु॑क्षीय॒ माऽमृता॑॑त् ।
ॐ स्वः भुवः भूः ॐ सः जूं हौं ॐ ।oṃ hauṃ jūṃ saḥ oṃ bhūrbhuvaḥ svaḥ ।
oṃ tryámbakaṃ yajāmahe sughandhíṃ puṣṭivardhánam ।
urvārukam iva bandhánān mṛtyor mukṣīya māmṛtāt ।
oṃ svaḥ bhuvaḥ bhūḥ oṃ saḥ jūṃ hauṃ ।
There's another version called the Short Mṛtyunjaya Mantra (लघु मृत्युंजय मंत्र):
ॐ जूं स माम् पालय पालय स: जूं ॐ ।
oṃ jūṃ sa mām pālaya pālaya sa: jūṃ oṃ ।
Question - Please provide the scriptural references for all the three versions of the Mantra, which scriptures have these? Furthermore, please explain the difference in usages of these three versions in terms of theology, benefits, and associated rituals.