R. D. Cortina

• Cortina method conversational Brazilian-Portuguese
• Inglês em 20 lições. English in 20 lessons for Portuguese speakers
• Brazilian-Portuguese conversation course
• Conversational modern Greek in 20 lessons
• Cortina handy dictionary, Spanish-English, English-Spanish =
• Cortina method Italian in 20 lessons
• Spanish in 20 lessons, illustrated
• Conversational French 20 Lessons
• Conversational Italian in 20 Lessons
• Conversational Japanese in 20 Lessons
• Conversational Russian in 20 lessons
• Conversational Spanish 20 Lessons