diff --git a/src/lib.rs b/src/lib.rs
index 4ec74eb..9a0e527 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -217,21 +217,16 @@ pub struct Sheet {
 
 /// Row to use as header
 /// By default, the first non-empty row is used as header
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Default, Clone, Copy)]
 #[non_exhaustive]
 pub enum HeaderRow {
     /// First non-empty row
+    #[default]
     FirstNonEmptyRow,
     /// Index of the header row
     Row(u32),
 }
 
-impl Default for HeaderRow {
-    fn default() -> Self {
-        HeaderRow::FirstNonEmptyRow
-    }
-}
-
 // FIXME `Reader` must only be seek `Seek` for `Xls::xls`. Because of the present API this limits
 // the kinds of readers (other) data in formats can be read from.
 /// A trait to share spreadsheets reader functions across different `FileType`s
diff --git a/src/xlsx/cells_reader.rs b/src/xlsx/cells_reader.rs
index 53d80a0..4c907ff 100644
--- a/src/xlsx/cells_reader.rs
+++ b/src/xlsx/cells_reader.rs
@@ -359,17 +359,8 @@ fn read_v<'s>(
             Ok(DataRef::DateTimeIso(v))
         }
         Some(b"str") => {
-            // see http://officeopenxml.com/SScontentOverview.php
-            // str - refers to formula cells
-            // * <c .. t='v' .. > indicates calculated value (this case)
-            // * <c .. t='f' .. > to the formula string (ignored case
-            // TODO: Fully support a Data::Formula representing both Formula string &
-            // last calculated value?
-            //
-            // NB: the result of a formula may not be a numeric value (=A3&" "&A4).
-            // We do try an initial parse as Float for utility, but fall back to a string
-            // representation if that fails
-            v.parse().map(DataRef::Float).or(Ok(DataRef::String(v)))
+            // string
+            Ok(DataRef::String(v))
         }
         Some(b"n") => {
             // n - number
diff --git a/tests/string-ref.xlsx b/tests/string-ref.xlsx
new file mode 100644
index 0000000..780d83c
Binary files /dev/null and b/tests/string-ref.xlsx differ
diff --git a/tests/test.rs b/tests/test.rs
index b74d89e..4faf6b7 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -2125,3 +2125,16 @@ fn test_no_header(#[case] header_row: HeaderRow, #[case] expected: &[[Data; 2]])
         .unwrap();
     range_eq!(range, expected);
 }
+
+#[test]
+fn test_string_ref() {
+    let mut xlsx: Xlsx<_> = wb("string-ref.xlsx");
+    let expected_range = [
+        [String("col1".to_string())],
+        [String("-8086931554011838357".to_string())],
+    ];
+    // first sheet
+    range_eq!(xlsx.worksheet_range_at(0).unwrap().unwrap(), expected_range);
+    // second sheet is the same with a cell reference to the first sheet
+    range_eq!(xlsx.worksheet_range_at(1).unwrap().unwrap(), expected_range);
+}