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I am looking for all finite groups $G$ such that for each subgroup $H$ of $G$ and each automorphism $\sigma$ of $H$ there exists an automorphism $\psi$ of $G$ whose restriction to $H$ is $\sigma$. Is there any reference on this problem?

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up vote 4 down vote accepted

These groups are called the groups of injective type. It is known that nonabelian finite groups of injective type have even order.

See the following papers:

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Thank so much for your answer. – majid arezoomand May 25 '13 at 10:19
You are welcome @majid-arezoomand – Name May 25 '13 at 13:54

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