diff --git a/json2.cabal b/json2.cabal
--- a/json2.cabal
+++ b/json2.cabal
@@ -1,5 +1,5 @@
 Name:                json2
-Version:             0.8.2
+Version:             0.8.3
 Synopsis:            Library provides support for JSON. 
 Category:            Data, Text, JSON
 Description:         This library provides support for JSON.
diff --git a/src/Data/JSON2.hs b/src/Data/JSON2.hs
--- a/src/Data/JSON2.hs
+++ b/src/Data/JSON2.hs
@@ -3,16 +3,8 @@
 {-# LANGUAGE IncoherentInstances #-}
 {-# LANGUAGE DeriveDataTypeable #-}
 {-|
-1. /Pretty prints/
 
-Re-export module Data.JSON2.Pretty. Example of use:
-
-@
-    *ghci>  pp $ mkObj [(show x, x) | x <- [0..7]]
-    {"0": 0, "1": 1, "2": 2, "3": 3, "4": 4, "5": 5, "6": 6, "7": 7}
-@
-
-2. /Renders JSON to String/
+1. /Renders JSON to String/
 
 Haskell value has a JSON string:
 
@@ -31,7 +23,7 @@
         :: Map String Int
 @
 
-3. /Conversion haskell values from and to JSON/
+2. /Conversion haskell values from and to JSON/
 
 This module provides many instances classes `FromJson` and `ToJson`
 for haskell data types.
@@ -77,8 +69,9 @@
 -}
 
 module Data.JSON2
-  ( -- * Re-export module for pretty printing
-    module Data.JSON2.Pretty 
+  ( -- * Re-export modules
+    module Data.JSON2.Pretty
+  , module Data.JSON2.Internal 
     -- * Base data types
   , Json (..)
   , Jsons (..)
@@ -92,6 +85,8 @@
   , emptyObj,  (.=), mkObj
     -- * Merges JSON objects
   , (+=), merges, mergeRec
+    -- * Query
+  , projectionObj
   )
 where
 
@@ -108,6 +103,7 @@
 import qualified Data.Map as Map
 import Data.Set (Set)
 import qualified Data.Set as Set
+import Data.Maybe (catMaybes)
 
 import qualified Data.ByteString           as B   (ByteString)
 import qualified Data.ByteString.Lazy      as L   (ByteString)
@@ -139,20 +135,17 @@
 --  Building JSON objects
 
 -- | Create empty `Json` object.
---
--- > pp $ emptyObj   ==   {}
 emptyObj :: Json
 emptyObj = JObject Map.empty
 
 -- | Create single `Json` object.
---
--- >  pp ("key" .= (Just False))   ==   {"key": false}
 (.=) :: (ToJson v, Typeable v) => String  -> v -> Json
 k .= v = JObject $ Map.singleton k (toJson v)
 
 -- | Create `Json` object from list.
 --
--- >  pp $ mkObj [("a", "old"), ("a", "new"), ("bb", "other")]   == {"a": "new", "bb": "other"}
+-- >  ghci> pp $ mkObj [("a", "old"), ("a", "new"), ("bb", "other")]
+-- >  {"a": "new", "bb": "other"}
 mkObj :: (ToJson v, Typeable v) => [(String ,v)] -> Json
 mkObj xs = JObject $ Map.fromList (map (\(k,v) -> (k, toJson v)) xs)
 
@@ -160,11 +153,9 @@
 
 -- | Merge two  `JObject`. Other `Json` values interpreted as `emptyObj`.
 --
--- > pp $ ("a" .= "old") += ("a" .= "new") += ("bb" .= "other")  ==   {"a": "new", "bb": "other"}
---
--- > obj += emptyObj   ==   emptyObj += obj
--- > obj += obj   ==   emptyObj += obj   ==   obj += emptyObj  
--- > obj1 += (obj2 += obj3)   ==   (obj1 += obj2) += obj3
+-- > ghci > pp $ ("a" .= "old") += ("a" .= "new") += ("bb" .= "other")
+-- > {"a": "new", "bb": "other"}
+
 (+=) :: Json -> Json -> Json
 (+=) (JObject x ) (JObject y) = JObject $ Map.union y x
 (+=) (JObject x ) _           = JObject x
@@ -173,7 +164,8 @@
 
 -- | Merge `Json` objects from list.
 --
--- >  pp $ merges [("a" .= "old"), ("a" .= "new"), ("bb" .= "other")]   ==   {"a": "new", "bb": "other"}
+-- > ghci>  pp $ merges [("a" .= "old"), ("a" .= "new"), ("bb" .= "other")]
+-- > {"a": "new", "bb": "other"}
 merges :: [Json] -> Json
 merges = foldl (+=) emptyObj
 
@@ -185,6 +177,16 @@
 mergeRec' (JObject x) (JObject y) = JObject $  Map.unionWith mergeRec' x y
 mergeRec' _           js          = js
 
+-- | Projection `Json` object to list of `Json` .
+--
+-- > > pp $ projectionObj ["b", "c", "b"] $ mkObj [("a",1),("b", 2), ("c", 3)]
+-- > [2, 3, 2]
+projectionObj :: [String] -> Json ->  Jsons
+projectionObj ps (JObject m) = case (nub ps) \\ (Map.keys m) of
+                          [] -> catMaybes $ map (\k -> Map.lookup k m) ps
+                          _  -> []
+    where ks = Map.keys m
+projectionObj _ _ = []
 
 ------------------------- Instances -----------------------------
 
diff --git a/src/Data/JSON2/Instances/Time.hs b/src/Data/JSON2/Instances/Time.hs
--- a/src/Data/JSON2/Instances/Time.hs
+++ b/src/Data/JSON2/Instances/Time.hs
@@ -20,7 +20,6 @@
 module Data.JSON2.Instances.Time where
 
 import Data.JSON2
-import Data.JSON2.Internal
 import Data.Time
 import Data.Time.Clock.POSIX(POSIXTime) -- POSIXTime synonym NominalDiffTime
 import System.Locale (iso8601DateFormat, defaultTimeLocale)