diff --git a/src/build/csl.rs b/src/build/csl.rs
index 6ca99ce..f69758c 100644
--- a/src/build/csl.rs
+++ b/src/build/csl.rs
@@ -1,12 +1,12 @@
 use zip::ZipArchive;
 use mktemp::Temp;
 use std::path::PathBuf;
-use utils::get_exe_dir;
+use utils::{get_exe_dir, result_override};
 use std::fs::File;
 use std::io::{Read, Write};
 use config::consts::CSL_FILE_NAME;
 
-pub fn get_csl_path() -> PathBuf {
+fn get_csl_path() -> PathBuf {
     return get_exe_dir().join(CSL_FILE_NAME);
 }
 
@@ -15,19 +15,27 @@ fn get_temp_file() -> PathBuf {
     return Temp::new_file().expect("Failed to create temporary file").to_path_buf();
 }
 
+
+fn get_csl_data(csl_name: String) -> Result<String, String> {
+    let zip_file = try!(result_override(File::open(get_csl_path()), "Failed to read CSL zip".into()));
+    let mut archive = try!(result_override(ZipArchive::new(zip_file), "Failed to load zip file".into()));
+    debug_assert!(archive.len() >= 10);
+    let mut csl_zip_file = try!(result_override(archive.by_name(&format!("{}.csl", csl_name)), format!("Can't find CSL {}.", csl_name)));
+    debug_assert!(csl_zip_file.size() > 0);
+    let mut csl_buffer = String::new();
+    try!(result_override(csl_zip_file.read_to_string(&mut csl_buffer), "Failed to read CSL".into()));
+    return Ok(csl_buffer);
+}
+
+pub fn is_valid_csl(csl_name: String) -> bool {
+    return get_csl_data(csl_name).is_ok();
+}
+
+
 pub fn unpack_csl(csl_name: String) -> PathBuf {
     let file = get_temp_file();
-    let zip_file = File::open(get_csl_path()).expect("Failed to read CSL zip");
-    let mut archive = ZipArchive::new(zip_file).expect("Failed to load zip file");
-    debug_assert!(archive.len() >= 10);
-    let mut csl_zip_file = archive.by_name(&format!("{}.csl", csl_name)).expect(&format!(
-        "Failed to find CSL {}.",
-        csl_name
-    ));
-    debug_assert!(csl_zip_file.size() > 0);
     let mut csl_temp = File::create(&file).expect("Failed to open temporary file");
-    let mut csl_buffer = String::new();
-    csl_zip_file.read_to_string(&mut csl_buffer).expect("Failed to read CSL");
+    let mut csl_buffer = get_csl_data(csl_name).unwrap();
     csl_temp.write_all(csl_buffer.as_bytes()).expect("Failed to write CSL to temporary file");
     return file;
 }
diff --git a/src/build/mod.rs b/src/build/mod.rs
index d570d96..cf47a5c 100644
--- a/src/build/mod.rs
+++ b/src/build/mod.rs
@@ -1,6 +1,6 @@
 pub mod pandoc;
 pub mod process;
-mod csl;
+pub mod csl;
 
 use config::Config;
 
diff --git a/src/config/validate.rs b/src/config/validate.rs
index 040224d..d23f60d 100644
--- a/src/config/validate.rs
+++ b/src/config/validate.rs
@@ -1,10 +1,12 @@
 use serde_yaml::Value;
 use std::vec::Vec;
-
-pub type ValidationResult = Result<(), String>;
-
 use config::read;
 use config::validate_types::check_config_types;
+use utils::resolve_path;
+use build::csl::is_valid_csl;
+
+
+pub type ValidationResult = Result<(), String>;
 
 
 fn check_required_keys(config: Value) -> ValidationResult {
@@ -45,6 +47,26 @@ fn check_output_files(config: Value) -> ValidationResult {
     return Ok(());
 }
 
+fn check_references(config: Value) -> ValidationResult {
+    if config.get("references").is_none() {
+        return Ok(());
+    }
+    let references = config.get("references").unwrap();
+    let bibliography = resolve_path(references.get("bibliography").unwrap().as_str().unwrap().into());
+    let valid_extensions = vec!["bib", "bibtex", "copac", "json", "yaml", "enl", "xml", "wos", "medline", "mods", "ris"];
+    if !bibliography.exists() {
+        return Err(format!("Can't find bibliography at {}.", bibliography.display()));
+    }
+    if !valid_extensions.contains(&bibliography.extension().unwrap().to_str().unwrap()) {
+        return Err(format!("Bibliography extension must be one of {:?}.", valid_extensions));
+    }
+    let csl = references.get("csl").unwrap().as_str().unwrap();
+    if !is_valid_csl(csl.into()) {
+        return Err(format!("{} isnt a valid CSL config.", csl));
+    }
+    return Ok(());
+}
+
 pub fn unwrap_group(config: Value, funcs: Vec<&Fn(Value) -> ValidationResult>) -> ValidationResult {
     for func in funcs.iter() {
         try!(func(config.clone()));
@@ -56,6 +78,6 @@ pub fn unwrap_group(config: Value, funcs: Vec<&Fn(Value) -> ValidationResult>) -
 pub fn validate(config: Value) -> ValidationResult {
     return unwrap_group(
         config,
-        vec![&check_required_keys, &check_config_types, &check_input_files, &check_output_files]
+        vec![&check_required_keys, &check_config_types, &check_input_files, &check_output_files, &check_references]
     );
 }
diff --git a/src/utils.rs b/src/utils.rs
index 1a8780a..63b00ee 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,7 +1,7 @@
 use std::fmt::Debug;
 use std::process::exit;
 use std::io::{self, Write};
-use std::env::current_exe;
+use std::env::{current_exe, current_dir};
 use std::path::PathBuf;
 
 
@@ -40,3 +40,8 @@ pub fn get_exe_dir() -> PathBuf {
         .expect("Failed to get exe directory")
         .to_path_buf();
 }
+
+pub fn resolve_path(path: String) -> PathBuf {
+    let base_dir = current_dir().unwrap();
+    return base_dir.join(path);
+}
diff --git a/test-files/bib.yaml b/test-files/bib.yaml
new file mode 100644
index 0000000..5ca622d
--- /dev/null
+++ b/test-files/bib.yaml
@@ -0,0 +1,42 @@
+---
+references:
+- id: item1
+  type: book
+  author:
+  - family: Doe
+    given: John
+  issued:
+  - year: '2005'
+  title: First book
+  publisher: Cambridge University Press
+  publisher-place: Cambridge
+
+- id: item2
+  type: article-journal
+  author:
+  - family: Doe
+    given: John
+  issued:
+  - year: '2006'
+  title: Article
+  container-title: Journal of Generic Studies
+  page: '33-34'
+  volume: '6'
+
+- id: item3
+  type: chapter
+  author:
+  - family: Doe
+    given: John
+  - family: Roe
+    given: Jenny
+  editor:
+  - family: Smith
+    given: Sam
+  issued:
+  - year: '2007'
+  title: Why water is wet
+  container-title: Third book
+  publisher: Oxford University Press
+  publisher-place: Oxford
+...
diff --git a/test-files/mdp.yml b/test-files/mdp.yml
index 689d43d..819b5f6 100644
--- a/test-files/mdp.yml
+++ b/test-files/mdp.yml
@@ -8,3 +8,6 @@ input:
 output:
     pdf: output.pdf
 title: test title
+references:
+    bibliography: bib.yaml
+    csl: apaaaaa