@article{oai:ynu.repo.nii.ac.jp:00006852, author = {Nunokawa, Mamoru and Thomas, Derek Keith}, issue = {2}, journal = {Yokohama Mathematical Journal = 横濱市立大學紀要. D部門, 数学}, month = {}, note = {application/pdf, Let $f(z)$ be analytic in $D=¥{z:|z|<1¥}$ and $f(O)=0$. It is shown that if $|¥frac{f^{¥prime}(z)}{f^{¥prime}(z)}|<¥frac{¥sqrt{a}}{2}$ $(z¥in D)$ , where $¥sqrt{¥alpha}/2=2.5159¥cdots$ , then $f(z)$ is starlike in $D$ .}, pages = {111--113}, title = {ON A PROBLEM OF MILLER AND MOCANU}, volume = {40}, year = {1993} }