diff --git a/ass1-jpa/src/main/java/dst/ass1/jpa/dao/impl/TripDAO.java b/ass1-jpa/src/main/java/dst/ass1/jpa/dao/impl/TripDAO.java
index 8789bbc..b413793 100644
--- a/ass1-jpa/src/main/java/dst/ass1/jpa/dao/impl/TripDAO.java
+++ b/ass1-jpa/src/main/java/dst/ass1/jpa/dao/impl/TripDAO.java
@@ -2,12 +2,20 @@ package dst.ass1.jpa.dao.impl;
 
 import dst.ass1.jpa.dao.ITripDAO;
 import dst.ass1.jpa.model.ITrip;
+import dst.ass1.jpa.model.TripState;
 import dst.ass1.jpa.model.impl.Trip;
 
 import javax.persistence.EntityManager;
+import javax.persistence.criteria.CriteriaBuilder;
+import javax.persistence.criteria.CriteriaQuery;
+import javax.persistence.criteria.Predicate;
+import javax.persistence.criteria.Root;
 import java.util.Collection;
 import java.util.Date;
 
+import static dst.ass1.jpa.util.Constants.M_TRIP_CREATED;
+import static dst.ass1.jpa.util.Constants.M_TRIP_STATE;
+
 public class TripDAO extends GenericDAO<ITrip> implements ITripDAO {
     public TripDAO(EntityManager entityManager) {
         super(entityManager, Trip.class);
@@ -15,6 +23,26 @@ public class TripDAO extends GenericDAO<ITrip> implements ITripDAO {
 
     @Override
     public Collection<ITrip> findCancelledTrips(Date start, Date end) {
-        return null;
+        CriteriaBuilder criteriaBuilder = super.entityManager.getCriteriaBuilder();
+        CriteriaQuery<ITrip> criteriaQuery = criteriaBuilder.createQuery(ITrip.class);
+
+        Root<Trip> root = criteriaQuery.from(Trip.class);
+        criteriaQuery.select(root);
+
+        Predicate cancelled = criteriaBuilder.equal(root.get(M_TRIP_STATE), TripState.CANCELLED);
+        Predicate startRange = criteriaBuilder.greaterThan(root.get(M_TRIP_CREATED), start);
+        Predicate endRange = criteriaBuilder.lessThan(root.get(M_TRIP_CREATED), end);
+
+        if (start == null && end == null) {
+            criteriaQuery.where(cancelled);
+        } else if (start == null) {
+            criteriaQuery.where(criteriaBuilder.and(cancelled, endRange));
+        } else if (end == null) {
+            criteriaQuery.where(criteriaBuilder.and(cancelled, startRange));
+        } else {
+            criteriaQuery.where(criteriaBuilder.and(cancelled, startRange, endRange));
+        }
+
+        return super.entityManager.createQuery(criteriaQuery).getResultList();
     }
 }