No abstract given. Here are the first relevant paragraphs:
An encyclopedic author active during the reign of King Rāmapāla (ca. 1084–1126/1077–
ca. 1119) of the Pāla Dynasty, Abhayākaragupta is renowned for his erudition in a vast range of subjects in Buddhism. His expertise is especially prominent in, though not limited to, the area of Tantric Buddhism, as attested by the well-known "Garland Trilogy" (phreng ba skor gsum), i.e. his three major works on Tantric ritual (Vajrāvalī, Jyotirmañjarī, and Niṣpannayogāvalī), which exercised a great influence on the Buddhism of the later period in Nepal and Tibet.
The Peking bsTan 'gyur includes twenty-six works ascribed to Abhayākaragupta, of which twenty-three are in the domain of Tantra; the other three deal with non-Tantric Buddhism. Though most of these works are only available through Tibetan translation, some important texts of Abhayākaragupta are preserved in Sanskrit. The following works in Sanskrit have hitherto been edited: Niṣpannayogāvalī; Vajrāvalī; Jyotimañjarī; Ucchuṣmajambhalasādhana; Svādhiṣṭhānakramopadeśa. In addition, Sanskrit manuscripts are known to exist of the Pañcakramatātparyapañjikā Kramakaumudī, Kālacakrāvatāra, and Abhayapaddhati. According to some recent information, furthermore, Sanskrit manuscripts of the Āmnāyamañjarī, Munimatālaṅkāra and Madhyamakamañjarī have been discovered in Tibet 
The Amnāyamañjarī, which may be called the magnum opus of Abhayākaragupta, is a commentary on the Saṃpuṭodbhavatantra and an encyclopedic compendium of Indian Tantric Buddhism. According to Bühnemann, Abhayākaragupta undertook the composition of the Amnāyamañjarī before 1101 or 1108 C.E. (twenty-fifth regnal year of Rāmapāla) and completed it in 1113 or 1120 C.E (thirty-seventh year of Rāmapāla). As has been remarked, the Saṃpuṭodbhavatantra, though traditionally considered to be an Explanatory Tantra (vyākhyātantra) of the Hevajra and Saṃvara cycles, integrates many doctrinal and ritual elements adopted from several heterogeneous textual traditions such as that of the Guhyasamāja. Because of this "ecumenical" character of the Saṃpuṭodbhavatantra, the Amnāyamañjarī as its commentary also encompasses a great variety of subjects relating to the doctrine and ritual of Tantric Buddhism. The Amnāyamañjarī is referred to several times by Abhayākaragupta himself in his other works, such as the Munimatālaṅkāra,
Abhayapaddhati, Pañcakramatātparyapañjikā, and Vajrāvalī. In turn, the Āmnāyamañjarī
refers to his other works 
Though, as remarked above, the existence of a presumably complete Sanskrit manuscript of the Āmnāyamañjarī has been reported, it still remains inaccessible to us. However, a single folio fragment of this text has been recently identified in the collection of Sanskrit manuscripts in Göttingen. In this paper, we describe this manuscript fragment and present a critical edition and an annotated translation of the text contained in it. We also include as appendices an edition of the corresponding part of the Tibetan translation as well as parallel passages found in Kamalanātha's Ratnāvalī and Abhayākaragupta's Abhayapaddhati. (Tomabechi and Kano, Abhayākaragupta and the Āmnāyamañjarī, 22–23)
1. For the dates and works of Abhayākaragupta, see Erb 1997: 27–29: Bühnemann and Tachikawa 1991: Bühnemann 1992.
2. For bibliographical information on these works, see Bühnemann 1992: 123–125.
3. The Svādhiṣṭhānakramopadeśa (or Dvibhujasaṃvaropadeśa) was edited by Okuyama (1993).
4. The Centre for Tantric Studies at University of Hamburg is currently working on a joint project to the Abhayapaddhati in collaboration with CTRC (China Tibetology Research Centre). Tomabechi is preparing a critical edition of the Kramakaumudī based on the manuscript copy preserved at CTRC.
5. The latter text is not included in the bsTan 'gyur, but is mentioned by Abhayākaragupta himself in the Munimatālaṅkāra, D 145v6; P 179r8: mdor bsdus pa ni kho bos dbu ma'i snye mar phul du byung bar rnam par bshad do; Āmnāyamañjarī, D 28r1; P 31r2–3: 'di'i skye ba dang 'jig pa de dag kyang dbu ma'i snye mar nges par dpyad zin pas (P: pa'i) ... ; D 76v7–77r1; P 86v2-3: thsad ma gang gis 'di rang bzhin med pa nyid du bsgrub pa de ni bdag cag gis rgyas pa dang bcas par dbu ma'i snye mar nye bar bkod cing; D 162r5–6; P 179v1: bzlog pa kho na
las de kho na nyid 'di rnams so zhes dbu ma'i snye mar nges par dpyad zin to (P: te). See also Isoda 1984: 3 n. 14.
6. These texts are registered in the (unpublished) catalogue of microfilms kept at the CTRC in Beijing. Tomabechi confirmed the existence of the copies of these manuscripts during his visit to Beijing in May–June 2007.
7. Noguchi 1984 and Skorupski 1996: 201.
8. See Munimatālaṅkāra, D 89r4; P 93v2, D 218r7; P 287r4, Kramakaumudī, fol. 22v4, 27r1, 53v4. For the Abhayapaddhati see Bühnemann and Tachikawa 1991: xiv and Bühnemann 1992:123; and for the Vajrāvalī, see Bühnemann and Tachikawa 1991: xvi and Bühnemann 1992: 125.
(in ĀM D 72v3; P 82r2, D 97r1; P 108r7, D 188v7; P 208r5, D 24Or2; P 266v4, D 257v2; P 288r4, D 260r4; P 291r5–6), Jyotirmañjarī
(in ĀM D 24Or2; P 266v3, D 260r3; P 291r4), Madhyamakamañjarī
(in ĀM D 28r1; P 31r2–3, D 76v7-77r1; P 86v2–3, D 162r6; P 179v1; See note 6 above), Munimatālaṃkāra
(in ĀM D 12r3; P 13v3, D 24v5; P 27v2, D 24v6; P 27v4, D 33v4; P 37v1–2, D 41v7–42r1; P 47r2, D 52r1; P 56r6, D 77r1; P 86v3, D 112v5–6); P 125r3, D 174v7; P 193r8, D 225v3; P 249r2, D 270r1–2; P 302v6), Abhayapaddhati
(in ĀM D 77r1; P 86v2, D 209r2; P 229v8), Cakrasaṃvarābhisamaya
(in ĀM D 172v6; P 191r6–7, D 242v3; P 269v7).
Tomabechi, Tōru, and Kazuo Kano. "A Critical Edition and Translation of a Text Fragment from Abhayākaragupta's Āmnāyamañjarī: Göttingen, Cod.ms.sanscr.259b." Tantric Studies 1 (2008): 22–44.