Fix broken links

contracts/token/ERC721/ERC721.sol

@@ -253,7 +253,7 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable
      *
      * `_data` is additional data, it has no specified format and it is sent in call to `to`.
      *
-     * This internal function is equivalent to {safeTransfertFrom}, and can be used to e.g.
+     * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
      * implement alternative mecanisms to perform token transfer, such as signature-based.
      *
      * Requirements:
@@ -310,7 +310,7 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable
     }
 
     /**
-     * @dev Same as {_safeMint-address-uint256-}, with an additional `data` parameter which is forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
+     * @dev Same as {ERC721-_safeMint-address-uint256-}, with an additional `data` parameter which is forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
      */
     function _safeMint(address to, uint256 tokenId, bytes memory _data) internal virtual {
         _mint(to, tokenId);