Unity3D Editor : How to get other fields in PropertyDrawer.OnGUI

MyProperty.cs

using UnityEngine;

public class MyProperty : PropertyAttribute {
	
	public int intValue = 33;
	
	public float floatValue = 12.5f;
	
	public bool boolValue = true;
	
	public MyProperty() {}
	
	public MyProperty(int intValue, float floatValue, bool boolValue) {
		this.intValue = intValue;
		this.floatValue = floatValue;
		this.boolValue = boolValue;
	}
}

MyPropertyDrawer.cs

using UnityEditor;

[CustomPropertyDrawer(typeof(MyProperty))]
public class MyPropertyDrawer : PropertyDrawer {
	
	private float lineHeight = 16f;
	
	public override float GetPropertyHeight (SerializedProperty property, GUIContent label) {
		return base.GetPropertyHeight (property, label) + lineHeight * 5;
	}
	
	public override void OnGUI(Rect position, SerializedProperty property, GUIContent label) {
		MyProperty myProperty = attribute as MyProperty;
		
		EditorGUI.LabelField(position, "Property Int: " + myProperty.intValue);
		
		position.y += lineHeight;
		EditorGUI.LabelField(position, "Property Float: " + myProperty.floatValue);
		
		position.y += lineHeight;
		EditorGUI.LabelField(position, "Property Bool: " + myProperty.boolValue);
		
		// Get float value.
		SerializedProperty floatProperty = property.serializedObject.FindProperty("myFloat");
		position.y += lineHeight;
		EditorGUI.LabelField(position, "myFloat: " + floatProperty.floatValue);
		
		// Get int value.
		SerializedProperty intProperty = property.serializedObject.FindProperty("myInt");
		position.y += lineHeight;
		EditorGUI.LabelField(position, "myInt: " + intProperty.intValue);
		
		// Get string value.
		SerializedProperty stringProperty = property.serializedObject.FindProperty("myString");
		position.y += lineHeight;
		EditorGUI.LabelField(position, "myString: " + stringProperty.stringValue);
		
		// Get object.
		SerializedProperty objectProperty = property.serializedObject.FindProperty("gameObject");
		GameObject gameObject = objectProperty.objectReferenceValue as GameObject;
	}

}

MyScript.cs

using UnityEngine;

public class MyScript : MonoBehaviour {
	
	public float myFloat = 1.2f;
	
	public int myInt = 1f;
	
	public string myString = "myString";
	
	public GameObject gameObject;
	
	[MyProperty]
	public int useByDrawer = 20;
	
	[MyProperty(1, 2.5f, false)]
	public int useByDrawer = 20;

}