There are two articles of comparatively recent origin which deal with this subject in desirable detail:
1)
Stinner, Susanne: Sāras, Saṃgrahas und 'Laghus': Kurzfassungen des
Mokṣopāya, in: The Mokṣopāya, Yogavāsiṣṭha and related texts: (based on
revised versions of lectures delivered at the "Mokṣopāya Panel" held at
the 29th German Oriental Conference in Halle), ed. by Jürgen Hanneder.
Aachen, 2005, S. 91-104.
2)
Hanneder, Jürgen: The Mokṣopāyasaṅgraha, in: The Mokṣopāya, Yogavāsiṣṭha
and related texts: (based on revised versions of lectures delivered at
the "Mokṣopāya Panel" held at the 29th German Oriental Conference in
Halle), ed. by Jürgen Hanneder. Aachen, 2005, S. 105-112.
Kind regards,
Walter Slaje