diff --git a/README.md b/README.md
index 5bd47fa..8a76afe 100644
--- a/README.md
+++ b/README.md
@@ -6,4 +6,6 @@
 
 RISC-V platform-level interrupt controller (PLIC) register definitions and basic operations.
 
-The official documentation: <https://github.com/riscv/riscv-plic-spec/blob/master/riscv-plic.adoc/>
\ No newline at end of file
+The official documentation: <https://github.com/riscv/riscv-plic-spec/blob/master/riscv-plic.adoc/>
+
+Ref: <https://github.com/YdrMaster/plic>
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index f10d91b..1ec1f0e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,5 @@
 //! RISC-V Platform-Level Interrupt Controller
-//! https://github.com/riscv/riscv-plic-spec/blob/master/riscv-plic.adoc
+//! <https://github.com/riscv/riscv-plic-spec/blob/master/riscv-plic.adoc>
 #![no_std]
 #![feature(const_option)]
 #![feature(const_nonnull_new)]
@@ -89,6 +89,7 @@ pub trait HartContext {
     fn index(self) -> usize;
 }
 
+/// Platform-Level Interrupt Controller.
 pub struct Plic {
     base: NonNull<PLICRegs>,
 }