diff --git a/satisfactory/__init__.py b/satisfactory/__init__.py
index 0b5dda9..d7aa1cd 100644
--- a/satisfactory/__init__.py
+++ b/satisfactory/__init__.py
@@ -21,19 +21,40 @@ class Cookbook(object):
         return self.__recipes[item]
 
     def all(self) -> Iterable[str]:
+        """
+        :return: An iterable of all available recipe names
+        """
         return self.__recipes.keys()
 
-    def recipes(self, name: str) -> Dict:
+    def recipes(self, name: str) -> Iterable[Dict]:
+        """
+        :param name: The target item name
+        :return: A sequence of possible recipes for the target item
+        """
         return self.__recipes[name]['recipes']
 
     def is_component(self, name: str) -> bool:
+        """
+        :param name: The name of an item
+        :return: Whether the item is a component; ie, craftable.
+        """
         return 'component' in self.__recipes[name]['type']
 
     def components(self) -> Generator[str, None, None]:
+        """
+        :return: The names of all items that are resources.
+        """
         return (i for i in self.all() if self.is_component(i))
 
     def is_resource(self, name: str) -> bool:
+        """
+        :param name: The name of an item
+        :return: Whether the item must have harvested (rather than crafted)
+        """
         return 'resource' in self.__recipes[name]['type']
 
     def resources(self) -> Generator[str, None, None]:
+        """
+        :return: The names of all items that are resources.
+        """
         return (i for i in self.all() if self.is_resource(i))