diff --git a/knowledge base/cloud computing/aws/s3.md b/knowledge base/cloud computing/aws/s3.md
index 725eafc..e64bbf4 100644
--- a/knowledge base/cloud computing/aws/s3.md	
+++ b/knowledge base/cloud computing/aws/s3.md	
@@ -226,6 +226,8 @@ Examples: [1][lifecycle  configuration examples], [2][s3 lifecycle rules example
 - [Amazon S3 cost optimization for predictable and dynamic access patterns]
 - [Gateway Endpoints vs Internet Routing for S3]
 - [Understanding your AWS billing and usage reports for Amazon S3]
+- [Downloading objects]
+- [Download and upload objects with presigned URLs]
 
 ### Sources
 
@@ -254,6 +256,8 @@ Examples: [1][lifecycle  configuration examples], [2][s3 lifecycle rules example
 [Amazon S3 cost optimization for predictable and dynamic access patterns]: https://aws.amazon.com/blogs/storage/amazon-s3-cost-optimization-for-predictable-and-dynamic-access-patterns/
 [amazon s3 storage classes]: https://aws.amazon.com/s3/storage-classes/
 [cli subcommand reference]: https://docs.aws.amazon.com/cli/latest/reference/s3/
+[Download and upload objects with presigned URLs]: https://docs.aws.amazon.com/AmazonS3/latest/userguide/using-presigned-url.html
+[Downloading objects]: https://docs.aws.amazon.com/AmazonS3/latest/userguide/download-objects.html
 [expiring amazon s3 objects based on last accessed date to decrease costs]: https://aws.amazon.com/blogs/architecture/expiring-amazon-s3-objects-based-on-last-accessed-date-to-decrease-costs/
 [find out the size of your amazon s3 buckets]: https://aws.amazon.com/blogs/storage/find-out-the-size-of-your-amazon-s3-buckets/
 [how s3 intelligent-tiering works]: https://docs.aws.amazon.com/AmazonS3/latest/userguide/intelligent-tiering-overview.html