diff --git a/II/Referatas/Makefile b/II/Referatas/Makefile
index ff198a9..8d3c417 100644
--- a/II/Referatas/Makefile
+++ b/II/Referatas/Makefile
@@ -3,7 +3,8 @@ GEN = $(addsuffix .pdf, \
 		  $(addprefix zeimena-douglas-,$(TOLERANCES)) \
 		  $(addprefix zeimena-visvalingam-,$(TOLERANCES)))
 
-mj-referatas.pdf: mj-referatas.tex version.tex bib.bib zeimena-pretty.pdf $(GEN)
+mj-referatas.pdf: mj-referatas.tex version.tex bib.bib zeimena-pretty.pdf \
+	sinewave-douglas-100.pdf $(GEN)
 	latexmk -g -pdf $<
 
 define algo2img
@@ -15,17 +16,18 @@ $(1)-$(2)-$(3).pdf: layer2img.py db/.faux_$(1)-$(2)-$(3)
 	./layer2img.py --table=$(1)_$(2)_$(3) --size=52x74 --outfile $(1)-$(2)-$(3).pdf
 endef
 
+$(eval $(call algo2img,sinewave,douglas,100))
 $(foreach t,$(TOLERANCES),$(eval $(call algo2img,zeimena,douglas,$(t))))
 $(foreach t,$(TOLERANCES),$(eval $(call algo2img,zeimena,visvalingam,$(t))))
 
-sinewave.json: sinewave.py
+sinewave.gpkg: sinewave.py
 	./sinewave.py
 
-db/.faux_ready: zeimena.gpkg sinewave.json managedb
+db/.faux_ready: zeimena.gpkg sinewave.gpkg managedb
 	-./managedb stop; rm -fr db
 	./managedb init
 	ogr2ogr -f PostgreSQL "PG:host=127.0.0.1 user=osm dbname=osm" zeimena.gpkg
-	ogr2ogr -f PostgreSQL "PG:host=127.0.0.1 user=osm dbname=osm" sinewave.json
+	ogr2ogr -f PostgreSQL "PG:host=127.0.0.1 user=osm dbname=osm" sinewave.gpkg
 	touch $@
 
 REF = $(shell git describe --tags)
diff --git a/II/Referatas/douglas.sql b/II/Referatas/douglas.sql
index ef997e2..6d4a8bb 100644
--- a/II/Referatas/douglas.sql
+++ b/II/Referatas/douglas.sql
@@ -7,8 +7,8 @@ CREATE TABLE :tbl (
 
 INSERT INTO :tbl (geom) (
     SELECT
-        ST_Simplify (ST_LineMerge (ST_Union (geom)),
-            :tolerance) AS geoms
+        ST_Multi (ST_Simplify (ST_LineMerge (ST_Union (geom)),
+                :tolerance)) AS geoms
     FROM
         :src);
 
diff --git a/II/Referatas/sinewave.py b/II/Referatas/sinewave.py
index e718d90..8a4923b 100755
--- a/II/Referatas/sinewave.py
+++ b/II/Referatas/sinewave.py
@@ -3,7 +3,7 @@ from math import pi
 from pyproj import CRS
 import numpy as np
 import geopandas as gpd
-from shapely.geometry import LineString
+from shapely.geometry import LineString, MultiLineString
 
 INTERVAL = 0.1
 TAIL_LEN = 4
@@ -17,11 +17,12 @@ def main():
     amplitude = (np.sin(sin_range * pi / 2) + 1)*2
     y = np.concatenate([TAILS, amplitude, TAILS])
     x = np.arange(-TAIL_LEN - pi/4, SINE_LEN + TAIL_LEN, INTERVAL)
-    geom = LineString(zip(x, y))
+    lines = LineString(zip(x, y))
+    geom = MultiLineString([lines])
     df = gpd.GeoDataFrame(crs=CRS(3346))
     df['geometry'] = None
     df.loc[0, 'geometry'] = geom
-    df.to_file("sinewave.json", driver='GeoJSON')
+    df.to_file("sinewave.gpkg", driver='GPKG')
 
 
 if __name__ == '__main__':
diff --git a/II/Referatas/visvalingam.sql b/II/Referatas/visvalingam.sql
index 340ce1d..31668cb 100644
--- a/II/Referatas/visvalingam.sql
+++ b/II/Referatas/visvalingam.sql
@@ -7,8 +7,8 @@ CREATE TABLE :tbl (
 
 INSERT INTO :tbl (geom) (
     SELECT
-        ST_SimplifyVW (ST_LineMerge (ST_Union (geom)),
-            :tolerance * :tolerance) AS geoms
+        ST_Multi (ST_SimplifyVW (ST_LineMerge (ST_Union (geom)),
+                :tolerance * :tolerance)) AS geoms
     FROM
         :src);