diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 6898f16..639b3c9 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -26,6 +26,6 @@ jobs:
       - name: Build
         run: cargo build --verbose
       - name: Run tests
-        run: cargo test --verbose
+        run: cargo test --features=std
       - name: Run clippy
         run: cargo clippy -- -Dclippy::all -Dclippy::cargo
diff --git a/src/hyperloglog_array.rs b/src/hyperloglog_array.rs
index 2c1686f..58b1a93 100644
--- a/src/hyperloglog_array.rs
+++ b/src/hyperloglog_array.rs
@@ -367,9 +367,9 @@ impl<
             "in the HyperLogLogArray."
         ));
         let mut array = [HyperLogLog::new(); N];
-        for (i, item) in items.into_iter().enumerate() {
-            for item in item.into_iter() {
-                array[i].insert(&item);
+        for (i, item) in items.iter().enumerate() {
+            for item in item.iter() {
+                array[i].insert(item);
             }
         }
         Self { counters: array }
diff --git a/src/hyperloglog_trait.rs b/src/hyperloglog_trait.rs
index 6321a33..bf37693 100644
--- a/src/hyperloglog_trait.rs
+++ b/src/hyperloglog_trait.rs
@@ -192,80 +192,6 @@ pub trait HyperLogLogTrait<PRECISION: Precision + WordType<BITS>, const BITS: us
         Self::adjust_estimate(raw_estimate)
     }
 
-    fn second_order_cardinality_adjustment(&self) -> f32 {
-        assert!(PRECISION::EXPONENT == 8);
-        assert!(BITS == 6);
-        let approximation = self.estimate_cardinality();
-        let number_of_zeros = self.get_number_of_zero_registers() as f32;
-        let number_of_zeros_rate =
-            self.get_number_of_zero_registers() as f32 / PRECISION::NUMBER_OF_REGISTERS as f32;
-
-        let weights = [0.9228072, 0.0052479184, 0.16169931];
-        let bias = 13.130121;
-
-        ([approximation, number_of_zeros, number_of_zeros_rate]
-            .iter()
-            .zip(weights.iter())
-            .map(|(x, w)| x * w)
-            .sum::<f32>()
-            + bias)
-            .max(0.0)
-    }
-
-    fn second_order_union_adjustment(&self, other: &Self) -> EstimatedUnionCardinalities<f32> {
-        assert!(PRECISION::EXPONENT == 8);
-        assert!(BITS == 6);
-        let euc: EstimatedUnionCardinalities<f32> = self.estimate_union_and_sets_cardinality(other);
-        let approximation_left_cardinality = euc.get_left_cardinality();
-        let approximation_right_cardinality = euc.get_right_cardinality();
-        let approximation_union_cardinality = euc.get_union_cardinality();
-        let approximation_intersection_cardinality = euc.get_intersection_cardinality();
-        let approximation_left_difference = euc.get_left_difference_cardinality();
-        let approximation_right_difference = euc.get_right_difference_cardinality();
-        let approximation_symmetric_difference = euc.get_symmetric_difference_cardinality();
-        let left_number_of_zeros = self.get_number_of_zero_registers();
-        let right_number_of_zeros = other.get_number_of_zero_registers();
-
-        let input = [
-            approximation_left_cardinality as f32,
-            approximation_right_cardinality as f32,
-            approximation_union_cardinality as f32,
-            approximation_left_difference as f32,
-            approximation_right_difference as f32,
-            approximation_symmetric_difference as f32,
-            approximation_intersection_cardinality as f32,
-            left_number_of_zeros as f32,
-            right_number_of_zeros as f32,
-        ];
-
-        let weights = [
-            -0.4552027,
-            0.87494165,
-            0.41451707,
-            1.0906912,
-            -0.23572926,
-            -0.13723965,
-            0.08993981,
-            -3.9901836,
-            -1.0626647,
-        ];
-        let bias = 12.55702;
-
-        let adjusted_union = (input
-            .iter()
-            .zip(weights.iter())
-            .map(|(x, w)| x * w)
-            .sum::<f32>()
-            + bias)
-            .max(0.0);
-
-        EstimatedUnionCardinalities::from((
-            approximation_left_cardinality,
-            approximation_right_cardinality,
-            adjusted_union,
-        ))
-    }
-
     #[inline(always)]
     /// Returns an estimate of the cardinality of the union of two HyperLogLog counters.
     ///