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### Volume 57, Number 7

#### Publication Date: 1981

Miscellaneous front pages, Proc. Japan Acad. Ser. A Math. Sci., Volume 57, Number 7 (1981)

A remark on the Hadamard variational formula, II

Daisuke Fujiwara; 337-341

The $\tau$ function of the Kadomtsev-Petviashvili equation transformation groups for soliton equations, I

Masaki Kashiwara and Tetsuji Miwa; 342-347

A note on quasilinear evolution equations, II

Kiyoko Furuya; 348-351

“Borel” lines for meromorphic solutions of the difference equation $y \left( {x + 1} \right) = y \left( x \right) + 1 + \lambda / y \left( x \right)$

Niro Yanagihara; 352-355

A remark on the boundary behavior of quasiconformal mappings and the classification of Riemann surfaces

Hiroshige Shiga; 356-358

On the neighbourhood of a Hopf surface

Hajime Tsuji; 359-362

Class number calculation and elliptic unit, III. Sextic case

Ken Nakamula; 363-366

Corrections to references [2] and [3]

Ken Nakamula; 366

On Richardson classes of unipotent elements in semisimple algebraic groups

Takeshi Hirai; 367-372

Modular forms of degree $n$ and representation by quadratic forms, III. Kloosterman's method

Yoshiyuki Kitaoka; 373-377

On the Galois cohomology groups of ${C_K} / {D_K}$

Shin-ichi Katayama; 378-380

A variational problem relating to the theory of optimal economic growth

Toru Maruyama; 381-386

Miscellaneous back pages, Proc. Japan Acad. Ser. A Math. Sci., Volume 57, Number 7 (1981)