diff --git a/R/cite.R b/R/cite.R
index 23e5f0bb..2dec779f 100644
--- a/R/cite.R
+++ b/R/cite.R
@@ -12,17 +12,17 @@
 #' @examples
 #' # Cite everything in all formats
 #' \dontrun{
-#'  spod_cite()
+#' spod_cite()
 #' }
 #'
 #' # Cite just the package in BibTeX format
 #' \dontrun{
-#'  spod_cite(what = "package", format = "bibtex")
+#' spod_cite(what = "package", format = "bibtex")
 #' }
 #'
 #' # Cite both methodologies in plain text
 #' \dontrun{
-#'  spod_cite(what = c("methodology_v1", "methodology_v2"), format = "text")
+#' spod_cite(what = c("methodology_v1", "methodology_v2"), format = "text")
 #' }
 spod_cite <- function(
   what = "all",
@@ -53,11 +53,27 @@ spod_cite <- function(
   format <- setdiff(format, "all")
 
   # 4. Get the citation object
-  cit <- utils::citation("spanishoddata")
+  cit <- tryCatch(
+    {
+      suppressWarnings(utils::citation("spanishoddata"))
+    },
+    error = function(e) {
+      # Fallback for devtools::load_all() or test environments
+      citation_file <- system.file("CITATION", package = "spanishoddata")
+      if (citation_file == "") {
+        stop("CITATION file not found.")
+      }
+      readCitationFile(citation_file, meta = list(Encoding = "UTF-8"))
+    }
+  )
 
   # 5. Function to get citation by key
   get_citation_by_key <- function(key) {
-    idx <- which(sapply(cit, function(x) x$key == key))
+    idx <- which(purrr::map_lgl(cit, function(x) {
+      # Try multiple ways to access the key
+      entry_key <- x$key %||% attr(x, "key") %||% x[["key"]]
+      isTRUE(entry_key == key)
+    }))
     if (length(idx) > 0) {
       return(cit[idx])
     }
diff --git a/tests/testthat/test-cite.R b/tests/testthat/test-cite.R
new file mode 100644
index 00000000..7b643852
--- /dev/null
+++ b/tests/testthat/test-cite.R
@@ -0,0 +1,124 @@
+# Load testthat
+library(testthat)
+
+# --- Tests for spod_cite function ---
+
+test_that("spod_cite with default arguments prints all citations in all formats", {
+  # Capture the output of a single function call
+  output <- capture.output(spod_cite())
+  output_str <- paste(output, collapse = "\n")
+
+  # Run all checks on the captured string
+  expect_true(grepl("Plain text citations:", output_str))
+  expect_true(grepl("Markdown citations:", output_str))
+  expect_true(grepl("BibTeX citations:", output_str))
+  expect_true(grepl("To cite the spanishoddata package", output_str))
+  expect_true(grepl(
+    "To cite the Ministry's mobility study website",
+    output_str
+  ))
+  expect_true(grepl("To cite the methodology for 2020-2021 data", output_str))
+  expect_true(grepl(
+    "To cite the methodology for 2022 and onwards data",
+    output_str
+  ))
+})
+
+test_that("spod_cite with specific 'what' and 'format' arguments works", {
+  # Capture the specific output to a string for inspection
+  output <- capture.output(spod_cite(what = "package", format = "bibtex"))
+  output_str <- paste(output, collapse = "\n")
+
+  # Check for expected content
+  expect_true(grepl("BibTeX citations:", output_str))
+  expect_true(grepl("%% To cite the spanishoddata package", output_str))
+  expect_true(grepl("@Manual", output_str))
+
+  # Check that other content is NOT present
+  expect_false(grepl("Plain text citations:", output_str))
+  expect_false(grepl("Markdown citations:", output_str))
+  expect_false(grepl(
+    "To cite the Ministry's mobility study website",
+    output_str
+  ))
+})
+
+test_that("spod_cite with multiple 'what' arguments works", {
+  output <- capture.output(spod_cite(
+    what = c("methodology_v1", "data"),
+    format = "text"
+  ))
+  output_str <- paste(output, collapse = "\n")
+
+  # Check for expected content
+  expect_true(grepl("Plain text citations:", output_str))
+  expect_true(grepl(
+    "To cite the Ministry's mobility study website:",
+    output_str
+  ))
+  expect_true(grepl("To cite the methodology for 2020-2021 data:", output_str))
+
+  # Check that other content is NOT present
+  expect_false(grepl("To cite the spanishoddata package", output_str))
+  expect_false(grepl("BibTeX citations:", output_str))
+})
+
+test_that("spod_cite handles invalid inputs gracefully", {
+  # The function uses checkmate, which will throw an error on invalid input
+  expect_error(spod_cite(what = "invalid_input"))
+  expect_error(spod_cite(format = "invalid_format"))
+})
+
+
+test_that("spod_cite includes the special note for methodology_v2", {
+  # Text format
+  output_text <- capture.output(spod_cite(
+    what = "methodology_v2",
+    format = "text"
+  ))
+  expect_true(any(grepl(
+    "Note: A more up-to-date methodology document may be available",
+    output_text
+  )))
+
+  # Markdown format
+  output_md <- capture.output(spod_cite(
+    what = "methodology_v2",
+    format = "markdown"
+  ))
+  expect_true(any(grepl("> \\*\\*Note:\\*\\*", output_md)))
+
+  # BibTeX format
+  output_bib <- capture.output(spod_cite(
+    what = "methodology_v2",
+    format = "bibtex"
+  ))
+  expect_true(any(grepl(
+    "%% Note: A more up-to-date methodology document may be available",
+    output_bib
+  )))
+})
+
+test_that("spod_cite expands 'all' argument correctly", {
+  # Test 'all' in 'what'
+  output_what <- capture.output(spod_cite(
+    what = c("package", "all"),
+    format = "text"
+  ))
+  output_what_str <- paste(output_what, collapse = "\n")
+  expect_true(grepl("To cite the spanishoddata package", output_what_str))
+  expect_true(grepl(
+    "To cite the Ministry's mobility study website",
+    output_what_str
+  ))
+
+  # Test 'all' in 'format'
+  output_format <- capture.output(spod_cite(
+    what = "package",
+    format = c("text", "all")
+  ))
+  output_format_str <- paste(output_format, collapse = "\n")
+  expect_true(grepl("Plain text citations:", output_format_str))
+  expect_true(grepl("Markdown citations:", output_format_str))
+  expect_true(grepl("BibTeX citations:", output_format_str))
+})