Herbal for difficulty sleeping (insomnia)

ingredients:
Spinach leaves: ½ handheld
Kaki Kuda leaves : ½ handheld
Coriander: 1 teaspoon
Cumin: 1 teaspoon
Tamarind trengguli: 1 finger
Palm sugar to taste.
All material is boiled with 4 cups water, drink 1 cup before bed.
Sources:

Petunjuk Bertanam dan Kegunaan Kencur, Haryanto ,S.N., Karya Anda, Surabaya,  1991