I'm working on a new edition of a book which uses a very unusual style of bibliography: Entries are sorted in author-year fashion, but then numbered per author or group of authors, e.g.:
Milnor, J.:
1. Construction of universal bundles: I, Ann. Math., (2)63:272-284 (1956).
2. Construction of universal bundles: II, Ann. Math., (2)63: 430-436 (1956).
3. On manifolds homeomorphic to the 7-sphere, Ann. Math., (2)64: 399-405
(1956).
4. The theory of characteristic classes, mimeographed, Princeton University,
Princeton, N.J., 1957.
Milnor, J., and M. A. Kervaire:
1. Bernoulli numbers, homotopy groups, and a theorem of Rohlin, Proc. Intern.
Congr. Math., 1958.
Milnor, J., and E. Spanier:
1. Two remarks on fibre homotopy type, Pacific J. Math., 10: 585-590 (1960).
Citations are formatted as Milnor [3], and so on.
Is there any bibtex style for something strange as this? Or can this type of bibliography be created with biblatex without too much coding?

.bibformat or specifically about compiling with BibTeX. – lockstep Nov 23 '12 at 08:57