The dictionary is a must for language adventurers. It covers literary/non literary words and phrases in more than 20 languages. I highly recommend Professor Bliss's dictionary.

One of the better-kept secrets in English lit is the surviving poetry in Old English, the dialect of Old German which developed independently in Britain during the five centuries preceding the Norman invasion of 1066 and evolved into Middle English subsequently. The Old English meter is a stichic (i.e. non-stanzaic) variation of the Old Germanic head-rhyme on the head-stave common to Old Norse as well (still possibly descended from Gothic), which became pervasively and elaborately stylized under Celtic influence in Britain in the forms of riddles, runes and inscriptions as well as formally literary works. The best-known modern English examples are from Book 5 of The Lord of the Rings, including the one which begins

Down from Dunharrow in the dim morning
With thane and captain rode Thengel's son.

It's difficult to imagine that anyone will improve on Bliss's Introduction to the topic, where, Old English being a dead language, there can be no question of his statistics becoming obsolete, unless more Old English verses are discovered, which is at this point highly unlikely. His account of the only apparently anomalous hypermetric line/s, which he found to be metrically consistent with the rest of the poetical Old English corpus, is somewhat in apposition to commentaries which have sought to limit the hypermetric line to a five-stave maximum, because Bliss confirmed the survival of six-stave Old English hypermetric lines. Not that Bliss sought to explain the apparently random locations of these lines, which explanation must by now be also regarded as highly unlikely: so far from doing so, he stated categorically that we do not understand why hypermetric lines appear where they do.

I would recommend four supplementary sources: the Princeton Encyclopedia of Poetry and Poetics for context on Bliss's contribution to the field (start with the article on alliteration and follow the cross-references); the Mitchell/Robinson Guide's diagram of Sievers-scansion mechanics; the 10-unit syllabic-verse-weight system presented in Tolkien's "On Translating Beowulf," which I found crucial for understanding this meter's relatively obscure refinements, i.e. anacrusis and particularly resolved stress (partially definitive for the Sievers D and E verses); and the responsible source on the Old English verse-combination rules which I have not yet discovered--my only negative criticism of Bliss's Introduction is its having omitted to include an account of those rules.

Notwithstanding which objection, this book is an exemplarily economical and straightforward summation of what we know about an ancient meter which has remained influential-most prominently in Bob Dylan's "It's a Hard Rain's a-Gonna Fall" and "Sad-Eyed Lady of the Lowlands." Even Bruce Mitchell might agree that Alan Bliss has been Tolkien's very best pupil.