diff --git a/collocatordb.cc b/collocatordb.cc
index 6970501..9a23173 100644
--- a/collocatordb.cc
+++ b/collocatordb.cc
@@ -390,6 +390,8 @@
     void dump(uint32_t w1, uint32_t w2, int8_t dist);
     vector<Collocator> get_collocators(uint32_t w1);
     vector<Collocator> get_collocators(uint32_t w1, uint32_t max_w2);
+    vector<Collocator> get_collocation_scores(uint32_t w1, uint32_t w2);
+    vector<Collocator> get_collocators(uint32_t w1, uint32_t min_w2, uint32_t max_w2);
     void applyCAMeasures(const uint32_t w1, const uint32_t w2,  uint64_t *sumWindow, const uint64_t sum, const int usedPositions, int true_window_size, rocksdb::Collocator *result);
 
     void dumpSparseLlr(uint32_t w1, uint32_t min_cooccur);
@@ -416,7 +418,7 @@
   rocksdb::CollocatorDB::CollocatorDB(const char *db_name, bool read_only = false) {
 		//		merge_option_.sync = true;
     if(read_only)
-      db_ = OpenDbForRead(db_name);
+      db_ = OpenDbForRead(strdup(db_name));
     else
       db_ = OpenDb(db_name);
     assert(db_);
@@ -538,7 +540,10 @@
     EncodeFixed64(prefixc, encodeCollocation(w1, w2, dist));
     Iterator *it = db_->NewIterator(options);
     CollocatorIterator *cit = new CollocatorIterator(it);
-    cit->Seek(std::string(prefixc,3));// it->Valid() && it->key().starts_with(std::string(prefixc,3)); it->Next()) {
+    if (w2 > 0)
+      cit->Seek(std::string(prefixc, 6));
+    else
+      cit->Seek(std::string(prefixc, 3));
     cit->setPrefix(prefixc);
     return cit;
   }
@@ -610,7 +615,7 @@
 
   }
 
-  std::vector<Collocator> rocksdb::CollocatorDB::get_collocators(uint32_t w1, uint32_t max_w2) {
+  std::vector<Collocator> rocksdb::CollocatorDB::get_collocators(uint32_t w1, uint32_t min_w2, uint32_t max_w2) {
     std::vector<Collocator> collocators;
     uint64_t w2, last_w2 = 0xffffffffffffffff;
     uint64_t maxv = 0, sum = 0;
@@ -628,7 +633,7 @@
 		#endif
 		// #pragma omp parallel num_threads(40)
 		// #pragma omp single
-    for ( auto it = std::unique_ptr<CollocatorIterator>(SeekIterator(w1, 0, 0)); it->isValid(); it->Next()) {
+    for ( auto it = std::unique_ptr<CollocatorIterator>(SeekIterator(w1, min_w2, 0)); it->isValid(); it->Next()) {
       uint64_t value = it->intValue(),
         key = it->intKey();
       if((w2 = W2(key)) > max_w2)
@@ -653,6 +658,8 @@
         maxv = value;
         sum = value;
         true_window_size = 1;
+	if (min_w2 == max_w2 && w2 != min_w2)
+	   break;
       } else {
         sum += value;
         if(value > maxv)
@@ -687,8 +694,13 @@
     return collocators;
   }
 
+
+  std::vector<Collocator> rocksdb::CollocatorDB::get_collocation_scores(uint32_t w1, uint32_t w2) {
+    return get_collocators(w1, w2, w2);
+  }
+
   std::vector<Collocator> rocksdb::CollocatorDB::get_collocators(uint32_t w1) {
-    return get_collocators(w1, UINT32_MAX);
+    return get_collocators(w1, 0, UINT32_MAX);
   }
 
   void rocksdb::CollocatorDB::dumpSparseLlr(uint32_t w1, uint32_t min_cooccur) {
@@ -799,11 +811,19 @@
 		db->get_collocators(w1);
 	}
 
+	void get_collocation_scores(COLLOCATORS *db, uint32_t w1, uint32_t w2) {
+		db->get_collocation_scores(w1, w2);
+	}
+
 	const char *get_word(COLLOCATORS *db, uint32_t w) {
-		return db->getWord(w).c_str();
+		return strdup(db->getWord(w).c_str());
 	}
 
 	const char *get_collocators_as_json(COLLOCATORS *db, uint32_t w1) {
 		return strdup(db->collocators2json(w1, db->get_collocators(w1)).c_str());
 	}
+
+	const char *get_collocation_scores_as_json(COLLOCATORS *db, uint32_t w1, uint32_t w2) {
+		return strdup(db->collocators2json(w1, db->get_collocation_scores(w1, w2)).c_str());
+	}
 }