diff --git a/tjnetwork.py b/tjnetwork.py
index 3877ccb..0a46c1e 100644
--- a/tjnetwork.py
+++ b/tjnetwork.py
@@ -540,6 +540,7 @@ def get_source(name: str, node: str) -> dict[str, Any]:
 def set_source(name: str, cs: ChangeSet) -> ChangeSet:
     return api.set_source(name, cs)
 
+# example: add_source(p, ChangeSet({'node': 'j0', 's_type': SOURCE_TYPE_CONCEN, 'strength': 10.0, 'pattern': 'p0'}))
 def add_source(name: str, cs: ChangeSet) -> ChangeSet:
     return api.add_source(name, cs)
 
@@ -592,6 +593,7 @@ def get_mixing(name: str, tank: str) -> dict[str, Any]:
 def set_mixing(name: str, cs: ChangeSet) -> ChangeSet:
     return api.set_mixing(name, cs)
 
+# example: add_mixing(p, ChangeSet({'tank': 't0', 'model': MIXING_MODEL_MIXED, 'value': 10.0}))
 def add_mixing(name: str, cs: ChangeSet) -> ChangeSet:
     return api.add_mixing(name, cs)