Ferdinand I as the Tsar (1908-1918). 10 stotinkas 1917, zinc, weight - 4 g., size - 19 mm, thickness - 1,5 mm., mintage - 59100000 pcs.
Tsar Boris III (1918-1943). 50 leva 1934, silver .500, weight - 10 g., size - 27 mm, mintage - 3000958 pcs. Engraver: Percival Metcalf. The single release only.
Ferdinand I as the Tsar (1908-1918). 5 stotinkas 1913, copper-nickel, weight - 3 g., size - 17 mm, thickness - 1,5 mm., mintage - 20000000 pcs. Viena Mint (Austria).
I got it today for $18. Prince Alexander I (1879-1886). 50 stotinkas 1883, silver .835, weight - 2,5 g., size - 18 mm, mintage - 3000000 pcs. Engraver: Nikolaj Formas. Minted in St. Petersburg, Russia. Single release only.
Peoples Republic of Bulgaria. 1 stotinka 1951, bronze alloy (brass), weight - 1 g., size - 15 mm, mintage - unknown. Minted in Leningrad (USSR) and Sofia (Bulgaria). Single release only.
1 stotinka 1962, bronze alloy (brass), weight - 1 g., size - 15 mm, mintage - unknown. Minted in Sofia (Bulgaria). Such coins were released at 1962 and 1970. Type: "9/11/1944 on ribbon".
1 stotinka 1974, bronze alloy (brass), weight - 1 g., size - 15 mm, mintage - unknown. Minted in Sofia (Bulgaria). Such coins were released at 1974, 1979-81 and 1988-90. Type: "Two dates on ribbon: "681-1944".
2 stotinkas 1962, bronze alloy (brass), weight - 2 g., size - 18 mm, mintage - unknown. Minted in Sofia (Bulgaria). Single release only. Type: "9/11/1944 on ribbon".
2 stotinkas 1974, bronze alloy (brass), weight - 2 g., size - 18 mm, mintage - unknown. Minted in Sofia (Bulgaria). Such coins were released at 1974, 1979-81 and 1988-90. Type: "Two dates on ribbon: "681-1944".
3 stotinkas 1951, bronze alloy (brass), weight - 2,4 g., size - 19 mm, mintage - unknown. Minted in Leningrad (USSR) and Sofia (Bulgaria). Single release only.
5 stotinkas 1951, bronze alloy (brass), weight - 3,1 g., size - 22 mm, mintage - unknown. Minted in Leningrad (USSR) and Sofia (Bulgaria). Single release only.
5 stotinkas 1962, bronze alloy (brass), weight - 3 g., size - 22 mm, mintage - unknown. Minted in Sofia (Bulgaria). Single release only. Type: "9/11/1944 on ribbon"
5 stotinkas 1974, bronze alloy (brass), weight - 3 g., size - 22 mm, mintage - unknown. Minted in Sofia (Bulgaria). Such coins were released at 1974, 1979-80 and 1988-90. Type: "Two dates on ribbon: "681-1944".
As for the stotinka coins from the 50s and 60s, the primary difference seems to be the style of the ear(s). I like the single and less abstract ear better, maybe only because it "breaks" the symmetrical design.
10 stotinkas 1951, copper-nickel, weight - 1,8 g., size - 17 mm, mintage - unknown. Minted in Leningrad (USSR) and Sofia (Bulgaria). Single release only.
10 stotinkas 1974, copper-nickel, weight - 1,6 g., size - 17 mm, mintage - unknown. Minted in Sofia (Bulgaria). Such coins were released at 1974, 1979-80 and 1988-90. Type: "Two dates on arms: "681-1944".
20 stotinkas 1952, copper-nickel, weight - 3 g., size - 21 mm, mintage - unknown. Minted in Sofia (Bulgaria). Price in Krause (F-VF-XF-Unc: $1-$2,5-$7,5-$20). 20 stotinkas 1954, copper-nickel, weight - 3 g., size - 21 mm, mintage - unknown. Minted in Sofia (Bulgaria). Price in Krause (F-VF-XF-Unc: $0,1-$o,25-$0,75-$1,5). But I don't know why the prices so differ.