diff --git a/src/wrappers/PhylorefWrapper.js b/src/wrappers/PhylorefWrapper.js
index f64b6573..e287a0c9 100644
--- a/src/wrappers/PhylorefWrapper.js
+++ b/src/wrappers/PhylorefWrapper.js
@@ -43,7 +43,7 @@ class PhylorefWrapper {
 
     normalizedPhyloref.internalSpecifiers = (phyloref.internalSpecifiers || [])
       .map(TaxonomicUnitWrapper.normalize);
-    normalizedPhyloref.externalSpecifiers = (phyloref.internalSpecifiers || [])
+    normalizedPhyloref.externalSpecifiers = (phyloref.externalSpecifiers || [])
       .map(TaxonomicUnitWrapper.normalize);
 
     return normalizedPhyloref;
diff --git a/src/wrappers/SpecimenWrapper.js b/src/wrappers/SpecimenWrapper.js
index 6888a00f..ce8ab8fb 100644
--- a/src/wrappers/SpecimenWrapper.js
+++ b/src/wrappers/SpecimenWrapper.js
@@ -29,6 +29,25 @@ class SpecimenWrapper {
     this.specimen = specimen;
   }
 
+  /**
+   * Normalize the specified specimen.
+   * @param specimen A specimen to be normalized.
+   */
+  static normalize(specimen) {
+    const wrapped = new SpecimenWrapper(specimen);
+    const normalizedSpecimen = {
+      '@type': SpecimenWrapper.TYPE_SPECIMEN,
+      label: wrapped.label,
+      'dwc:basisOfRecord': wrapped.basisOfRecord,
+      occurrenceID: wrapped.occurrenceID,
+      catalogNumber: wrapped.catalogNumber,
+      institutionCode: wrapped.institutionCode,
+      collectionCode: wrapped.collectionCode,
+    };
+    if ('@id' in specimen) normalizedSpecimen['@id'] = specimen['@id'];
+    return normalizedSpecimen;
+  }
+
   /**
    * Parse the provided occurrence ID. The two expected formats are:
    *  - 'urn:catalog:[institutionCode]:[collectionCode]:[catalogNumber]'
diff --git a/src/wrappers/TaxonConceptWrapper.js b/src/wrappers/TaxonConceptWrapper.js
index 9e4f3d19..91b21998 100644
--- a/src/wrappers/TaxonConceptWrapper.js
+++ b/src/wrappers/TaxonConceptWrapper.js
@@ -34,6 +34,23 @@ class TaxonConceptWrapper {
     this.defaultNomenCode = defaultNomenCode;
   }
 
+  /**
+   * Normalize the specified taxon concept.
+   * @param tc A taxon concept to be normalized.
+   */
+  static normalize(tc) {
+    const wrapped = new TaxonConceptWrapper(tc);
+    const normalizedTC = {
+      '@type': TaxonConceptWrapper.TYPE_TAXON_CONCEPT,
+      label: wrapped.label,
+      hasName: TaxonNameWrapper.normalize(wrapped.taxonName),
+      nameString: wrapped.taxonName.nameComplete,
+      accordingTo: wrapped.accordingTo,
+    };
+    if ('@id' in tc) normalizedTC['@id'] = tc['@id'];
+    return normalizedTC;
+  }
+
   /**
    * Return the taxon name of this taxon concept (if any) as an object.
    */
@@ -89,10 +106,10 @@ class TaxonConceptWrapper {
    */
   get accordingTo() {
     // Do we have any accordingTo information?
-    if (has(this.tunit, 'accordingTo')) return this.type.accordingTo;
+    if (has(this.tunit, 'accordingTo')) return this.tunit.accordingTo;
 
     // Do we have an accordingToString?
-    if (has(this.tunit, 'accordingToString')) return this.type.accordingToString;
+    if (has(this.tunit, 'accordingToString')) return this.tunit.accordingToString;
 
     // If not, we have no accodingTo information!
     return undefined;
@@ -106,10 +123,10 @@ class TaxonConceptWrapper {
    */
   get accordingToString() {
     // Do we have any accordingTo information?
-    if (has(this.tunit, 'accordingTo')) return JSON.stringify(this.type.accordingTo);
+    if (has(this.tunit, 'accordingTo')) return JSON.stringify(this.tunit.accordingTo);
 
     // Do we have an accordingToString?
-    if (has(this.tunit, 'accordingToString')) return this.type.accordingToString;
+    if (has(this.tunit, 'accordingToString')) return this.tunit.accordingToString;
 
     // If not, we have no accodingTo information!
     return undefined;
diff --git a/src/wrappers/TaxonNameWrapper.js b/src/wrappers/TaxonNameWrapper.js
index e70666fa..8dcfe3fd 100644
--- a/src/wrappers/TaxonNameWrapper.js
+++ b/src/wrappers/TaxonNameWrapper.js
@@ -143,6 +143,25 @@ class TaxonNameWrapper {
     return undefined;
   }
 
+  /**
+   * Normalize the specified taxon name.
+   * @param txname A taxon name to be normalized.
+   */
+  static normalize(txname) {
+    const wrapped = new TaxonNameWrapper(txname);
+    const normalizedTxname = {
+      '@type': TaxonNameWrapper.TYPE_TAXON_NAME,
+      nomenclaturalCode: wrapped.nomenclaturalCode,
+      label: wrapped.label,
+      nameComplete: wrapped.nameComplete,
+      genusPart: wrapped.genusPart,
+      specificEpithet: wrapped.specificEpithet,
+      infraspecificEpithet: wrapped.infraspecificEpithet,
+    };
+    if ('@id' in txname) normalizedTxname['@id'] = txname['@id'];
+    return normalizedTxname;
+  }
+
   /**
    * Returns the nomenclatural code of this taxon name.
    */
diff --git a/src/wrappers/TaxonomicUnitWrapper.js b/src/wrappers/TaxonomicUnitWrapper.js
index 7c63af18..26c7dcb2 100644
--- a/src/wrappers/TaxonomicUnitWrapper.js
+++ b/src/wrappers/TaxonomicUnitWrapper.js
@@ -59,6 +59,25 @@ class TaxonomicUnitWrapper {
     this.defaultNomenCode = defaultNomenCode;
   }
 
+  /**
+   * Normalize the specified taxonomic unit.
+   * @param tunit A taxonomic unit to be normalized.
+   */
+  static normalize(tunit) {
+    const wrapped = new TaxonomicUnitWrapper(tunit);
+    if (wrapped.taxonConcept) {
+      return TaxonConceptWrapper.normalize(tunit);
+    }
+    if (wrapped.specimen) {
+      return SpecimenWrapper.normalize(tunit);
+    }
+    if (wrapped.externalReferences) {
+      // External references should only have an `@id`.
+      return tunit;
+    }
+    return tunit;
+  }
+
   /**
    * What type of specifier is this? This is an array that could contain multiple
    * classes, but should contain one of: