Sino-Platonic Papers has rereleased for free issue no. 30 from October 1991: Chinese Philology and the Scripts of Central Asia (742 KB PDF), by M.V. Sofronov of the Institute of Far Eastern Studies, Academy of Sciences, Moscow.
It begins:
The period of the tenth to fourteenth centuries was a time when the peoples who conquered Northern China established their own states and proceeded to create their own written culture. They rightly saw the basis of a new state culture in their own script. The Kidan state of Liao was established in 916 in the northeastern part of China. It was conquered by the Jucen state Jin in 1126. The Tangut state of Hsi Hsia was established on the northwestern frontiers of China in 1032. All of these states created their cultures in accordance with historical circumstances and taking into consideration the achievements of older cultural centers of East and South Asia.
The oldest and most powerful philological tradition which exerted an influence on the scripts of Central Asia was that of the Chinese. This tradition developed under the specific conditions of the Chinese character script. Primarily, it elaborated the problem of the explanation of the meanings of the characters and the establishment of their correct readings.
One of the important achievements of the traditional Chinese philology was the method of fanqie (“cut and splice”) according to which the unknown reading of a character is described by means of two other characters with known readings. Originally fanqie was designed, presumably under the tutelage of Indian phoneticians, to indicate the readings of characters in the philological works. With the development of Tantric Buddhism in China it was extended to the transcription of Sanskrit dharanis and related texts. In these transcriptions, Sanskrit syllables with phonemic components distributively incompatible in Chinese were constructed. In these cases the Sanskrit syllable was rendered by two Chinese ones. This pair of Chinese syllables formed the fanqie binom provided with appropriate diacritics. For rendering initial consonant clusters, two or three Chinese syllables were used respectively for clusters of two or three Sanskrit consonants. These binoms or trinoms were provided with diacritics, respectively erhe (“two together”) or sanhe (“three together”). This method of transcription constituted the counterpart to the orthographic techniques of the rendering of consonant clusters in Sanskrit and Tibetan syllabic scripts….