Niro Yanagihara "“Borel” lines for meromorphic solutions of the difference equation $y \left( {x + 1} \right) = y \left( x \right) + 1 + \lambda / y \left( x \right)$," Proceedings of the Japan Academy, Series A, Mathematical Sciences, Proc. Japan Acad. Ser. A Math. Sci. 57(7), 352-355, (1981)