diff --git a/assign6.md b/assign6.md
index 2b64f105851e29677209aca42be4f576bbf9f30e..d683d3cb9e2478a8844c2fc0c158f9eaac535a83 100644
--- a/assign6.md
+++ b/assign6.md
@@ -21,7 +21,7 @@ The database system is written in Python and attempts to simulate how a database
 
 * `disk_relations.py`: This module contains the classes Block, RelationBlock, Relation, and a few others helper classes like Pointer. A Block is a base class, 
 that is subclassed by RelationBlock and BTreeBlock (in `btree.py` file). A RelationBlock contains a set of tuples, and a Relation contains a list of RelationBlocks. 
-* `queryprocessing.py`: This contains naive implementations of some of the query processing operators, including SequentialScan, NestedLoopsJoin, HashJoin, and SortMergeJoin. The operators are written using the iterator `get_next` interface, which is discussed in Chapter 12.7.2.1.
+* `queryprocessing.py`: This contains naive implementations of some of the query processing operators, including SequentialScan, NestedLoopsJoin, HashJoin, and SortMergeJoin. The operators are written using the iterator `get_next` interface, which is discussed in Chapter 15.7.
 
 
 ### How to Use the Files