This PDF file contains the complete book of the Serpent Power as listed below.
1) THE SIX CENTRES AND THE SERPENT POWER By WOODROFFE.
2) Ṣaṭ-Cakra-Nirūpaṇa, Six-Cakra Investigation: Description of and Investigation into the Six Bodily Centers by Tantrik Purnananda-Svami (1526 CE).
3) THE FIVEFOLD FOOTSTOOL (PĀDUKĀ-PAÑCAKA THE SIX CENTRES AND THE SERPENT POWER See the diagram in the next